diff --git a/gstreamer-check/Cargo.toml b/gstreamer-check/Cargo.toml
index 7ae9e9cf8..5cd6a5b36 100644
--- a/gstreamer-check/Cargo.toml
+++ b/gstreamer-check/Cargo.toml
@@ -11,29 +11,27 @@ homepage = "https://gstreamer.freedesktop.org"
 documentation = "https://gstreamer.pages.freedesktop.org/gstreamer-rs/gstreamer_check/"
 keywords = ["gstreamer", "multimedia", "audio", "video", "gnome"]
 build = "build.rs"
+edition = "2018"
 
 [dependencies]
 bitflags = "1.0"
-glib-sys = { git = "https://github.com/gtk-rs/gtk-rs" }
-gobject-sys = { git = "https://github.com/gtk-rs/gtk-rs" }
-gstreamer-sys = { path = "../gstreamer/sys", features = ["v1_8"]  }
-gstreamer-check-sys = { path = "../gstreamer-check/sys", features = ["v1_8"] }
+ffi = { package = "gstreamer-check-sys", path = "../gstreamer-check/sys", features = ["v1_8"] }
 glib = { git = "https://github.com/gtk-rs/gtk-rs" }
-gstreamer = { path = "../gstreamer" }
+gst = { package = "gstreamer", path = "../gstreamer" }
 
 [build-dependencies]
 gstreamer-rs-lgpl-docs = { path = "../docs", optional = true }
 
 [features]
 default = []
-v1_10 = ["gstreamer/v1_10", "gstreamer-check-sys/v1_10"]
-v1_12 = ["gstreamer/v1_12", "gstreamer-check-sys/v1_12", "v1_10"]
-v1_14 = ["gstreamer/v1_14", "gstreamer-check-sys/v1_14", "v1_12"]
-v1_16 = ["gstreamer/v1_16", "gstreamer-check-sys/v1_16", "v1_14"]
-v1_18 = ["gstreamer/v1_18", "gstreamer-check-sys/v1_18", "v1_16"]
+v1_10 = ["gst/v1_10", "ffi/v1_10"]
+v1_12 = ["gst/v1_12", "ffi/v1_12", "v1_10"]
+v1_14 = ["gst/v1_14", "ffi/v1_14", "v1_12"]
+v1_16 = ["gst/v1_16", "ffi/v1_16", "v1_14"]
+v1_18 = ["gst/v1_18", "ffi/v1_18", "v1_16"]
 embed-lgpl-docs = ["gstreamer-rs-lgpl-docs"]
 purge-lgpl-docs = ["gstreamer-rs-lgpl-docs"]
-dox = ["v1_18", "gstreamer-check-sys/dox", "glib/dox", "gstreamer/dox"]
+dox = ["v1_18", "ffi/dox", "glib/dox", "gst/dox"]
 
 [package.metadata.docs.rs]
 features = ["dox", "embed-lgpl-docs"]
diff --git a/gstreamer-check/src/harness.rs b/gstreamer-check/src/harness.rs
index 8e2948d99..028516d63 100644
--- a/gstreamer-check/src/harness.rs
+++ b/gstreamer-check/src/harness.rs
@@ -6,28 +6,23 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use glib;
+use crate::TestClock;
 use glib::object::IsA;
 use glib::translate::*;
-use glib_sys;
-use gobject_sys;
-use gst;
 use gst::prelude::*;
-use gst_check_sys;
 use std::marker::PhantomData;
 use std::mem;
 use std::ops;
 use std::path;
 use std::ptr;
-use TestClock;
 
 #[derive(Debug)]
-pub struct Harness(ptr::NonNull<gst_check_sys::GstHarness>);
+pub struct Harness(ptr::NonNull<ffi::GstHarness>);
 
 impl Drop for Harness {
     fn drop(&mut self) {
         unsafe {
-            gst_check_sys::gst_harness_teardown(self.0.as_ptr());
+            ffi::gst_harness_teardown(self.0.as_ptr());
         }
     }
 }
@@ -47,7 +42,7 @@ impl Harness {
         let element_sinkpad_name = element_sinkpad_name.to_glib_none();
         let element_srcpad_name = element_srcpad_name.to_glib_none();
         unsafe {
-            gst_check_sys::gst_harness_add_element_full(
+            ffi::gst_harness_add_element_full(
                 self.0.as_ptr(),
                 element.as_ref().to_glib_none().0,
                 hsrc.to_glib_none().0 as *mut _,
@@ -60,7 +55,7 @@ impl Harness {
 
     pub fn add_element_sink_pad<P: IsA<gst::Pad>>(&mut self, sinkpad: &P) {
         unsafe {
-            gst_check_sys::gst_harness_add_element_sink_pad(
+            ffi::gst_harness_add_element_sink_pad(
                 self.0.as_ptr(),
                 sinkpad.as_ref().to_glib_none().0,
             );
@@ -69,16 +64,13 @@ impl Harness {
 
     pub fn add_element_src_pad<P: IsA<gst::Pad>>(&mut self, srcpad: &P) {
         unsafe {
-            gst_check_sys::gst_harness_add_element_src_pad(
-                self.0.as_ptr(),
-                srcpad.as_ref().to_glib_none().0,
-            );
+            ffi::gst_harness_add_element_src_pad(self.0.as_ptr(), srcpad.as_ref().to_glib_none().0);
         }
     }
 
     pub fn add_parse(&mut self, launchline: &str) {
         unsafe {
-            gst_check_sys::gst_harness_add_parse(self.0.as_ptr(), launchline.to_glib_none().0);
+            ffi::gst_harness_add_parse(self.0.as_ptr(), launchline.to_glib_none().0);
         }
     }
 
@@ -107,39 +99,32 @@ impl Harness {
     ) {
         unsafe {
             let params = params.map(|p| p.as_ptr()).unwrap_or(ptr::null_mut());
-            gst_check_sys::gst_harness_add_propose_allocation_meta(
-                self.0.as_ptr(),
-                api.to_glib(),
-                params,
-            );
+            ffi::gst_harness_add_propose_allocation_meta(self.0.as_ptr(), api.to_glib(), params);
         }
     }
 
     pub fn add_sink(&mut self, sink_element_name: &str) {
         unsafe {
-            gst_check_sys::gst_harness_add_sink(
-                self.0.as_ptr(),
-                sink_element_name.to_glib_none().0,
-            );
+            ffi::gst_harness_add_sink(self.0.as_ptr(), sink_element_name.to_glib_none().0);
         }
     }
 
     pub fn add_sink_harness(&mut self, sink_harness: Harness) {
         unsafe {
             let sink_harness = mem::ManuallyDrop::new(sink_harness);
-            gst_check_sys::gst_harness_add_sink_harness(self.0.as_ptr(), sink_harness.0.as_ptr());
+            ffi::gst_harness_add_sink_harness(self.0.as_ptr(), sink_harness.0.as_ptr());
         }
     }
 
     pub fn add_sink_parse(&mut self, launchline: &str) {
         unsafe {
-            gst_check_sys::gst_harness_add_sink_parse(self.0.as_ptr(), launchline.to_glib_none().0);
+            ffi::gst_harness_add_sink_parse(self.0.as_ptr(), launchline.to_glib_none().0);
         }
     }
 
     pub fn add_src(&mut self, src_element_name: &str, has_clock_wait: bool) {
         unsafe {
-            gst_check_sys::gst_harness_add_src(
+            ffi::gst_harness_add_src(
                 self.0.as_ptr(),
                 src_element_name.to_glib_none().0,
                 has_clock_wait.to_glib(),
@@ -150,7 +135,7 @@ impl Harness {
     pub fn add_src_harness(&mut self, src_harness: Harness, has_clock_wait: bool) {
         unsafe {
             let src_harness = mem::ManuallyDrop::new(src_harness);
-            gst_check_sys::gst_harness_add_src_harness(
+            ffi::gst_harness_add_src_harness(
                 self.0.as_ptr(),
                 src_harness.0.as_ptr(),
                 has_clock_wait.to_glib(),
@@ -160,7 +145,7 @@ impl Harness {
 
     pub fn add_src_parse(&mut self, launchline: &str, has_clock_wait: bool) {
         unsafe {
-            gst_check_sys::gst_harness_add_src_parse(
+            ffi::gst_harness_add_src_parse(
                 self.0.as_ptr(),
                 launchline.to_glib_none().0,
                 has_clock_wait.to_glib(),
@@ -169,17 +154,17 @@ impl Harness {
     }
 
     pub fn buffers_in_queue(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_buffers_in_queue(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_buffers_in_queue(self.0.as_ptr()) }
     }
 
     pub fn buffers_received(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_buffers_received(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_buffers_received(self.0.as_ptr()) }
     }
 
     pub fn crank_multiple_clock_waits(&mut self, waits: u32) -> Result<(), glib::BoolError> {
         unsafe {
-            glib_result_from_gboolean!(
-                gst_check_sys::gst_harness_crank_multiple_clock_waits(self.0.as_ptr(), waits),
+            glib::glib_result_from_gboolean!(
+                ffi::gst_harness_crank_multiple_clock_waits(self.0.as_ptr(), waits),
                 "Failed to crank multiple clock waits",
             )
         }
@@ -187,8 +172,8 @@ impl Harness {
 
     pub fn crank_single_clock_wait(&mut self) -> Result<(), glib::BoolError> {
         unsafe {
-            glib_result_from_gboolean!(
-                gst_check_sys::gst_harness_crank_single_clock_wait(self.0.as_ptr()),
+            glib::glib_result_from_gboolean!(
+                ffi::gst_harness_crank_single_clock_wait(self.0.as_ptr()),
                 "Failed to crank single clock wait",
             )
         }
@@ -196,44 +181,38 @@ impl Harness {
 
     pub fn create_buffer(&mut self, size: usize) -> Result<gst::Buffer, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_create_buffer(
-                self.0.as_ptr(),
-                size,
-            ))
-            .ok_or_else(|| glib_bool_error!("Failed to create new buffer"))
+            Option::<_>::from_glib_full(ffi::gst_harness_create_buffer(self.0.as_ptr(), size))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to create new buffer"))
         }
     }
 
     pub fn dump_to_file<P: AsRef<path::Path>>(&mut self, filename: P) {
         let filename = filename.as_ref();
         unsafe {
-            gst_check_sys::gst_harness_dump_to_file(self.0.as_ptr(), filename.to_glib_none().0);
+            ffi::gst_harness_dump_to_file(self.0.as_ptr(), filename.to_glib_none().0);
         }
     }
 
     pub fn events_in_queue(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_events_in_queue(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_events_in_queue(self.0.as_ptr()) }
     }
 
     pub fn events_received(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_events_received(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_events_received(self.0.as_ptr()) }
     }
 
     pub fn find_element(&mut self, element_name: &str) -> Option<gst::Element> {
         unsafe {
             // Work around https://gitlab.freedesktop.org/gstreamer/gstreamer/merge_requests/31
-            let ptr = gst_check_sys::gst_harness_find_element(
-                self.0.as_ptr(),
-                element_name.to_glib_none().0,
-            );
+            let ptr = ffi::gst_harness_find_element(self.0.as_ptr(), element_name.to_glib_none().0);
 
             if ptr.is_null() {
                 return None;
             }
 
             // Clear floating flag if it is set
-            if gobject_sys::g_object_is_floating(ptr as *mut _) != glib_sys::GFALSE {
-                gobject_sys::g_object_ref_sink(ptr as *mut _);
+            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
+                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
             }
 
             from_glib_full(ptr)
@@ -241,77 +220,67 @@ impl Harness {
     }
 
     //pub fn get(&mut self, element_name: &str, first_property_name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_get() }
+    //    unsafe { TODO: call ffi::gst_harness_get() }
     //}
 
     //pub fn get_allocator(&mut self, allocator: /*Ignored*/gst::Allocator, params: /*Ignored*/gst::AllocationParams) {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_get_allocator() }
+    //    unsafe { TODO: call ffi::gst_harness_get_allocator() }
     //}
 
     pub fn get_last_pushed_timestamp(&self) -> gst::ClockTime {
-        unsafe {
-            from_glib(gst_check_sys::gst_harness_get_last_pushed_timestamp(
-                self.0.as_ptr(),
-            ))
-        }
+        unsafe { from_glib(ffi::gst_harness_get_last_pushed_timestamp(self.0.as_ptr())) }
     }
 
     pub fn get_testclock(&self) -> Option<TestClock> {
-        unsafe { from_glib_full(gst_check_sys::gst_harness_get_testclock(self.0.as_ptr())) }
+        unsafe { from_glib_full(ffi::gst_harness_get_testclock(self.0.as_ptr())) }
     }
 
     pub fn play(&mut self) {
         unsafe {
-            gst_check_sys::gst_harness_play(self.0.as_ptr());
+            ffi::gst_harness_play(self.0.as_ptr());
         }
     }
 
     pub fn pull(&mut self) -> Result<gst::Buffer, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_pull(self.0.as_ptr()))
-                .ok_or_else(|| glib_bool_error!("Failed to pull buffer"))
+            Option::<_>::from_glib_full(ffi::gst_harness_pull(self.0.as_ptr()))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to pull buffer"))
         }
     }
 
     pub fn pull_event(&mut self) -> Result<gst::Event, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_pull_event(self.0.as_ptr()))
-                .ok_or_else(|| glib_bool_error!("Failed to pull event"))
+            Option::<_>::from_glib_full(ffi::gst_harness_pull_event(self.0.as_ptr()))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to pull event"))
         }
     }
 
     pub fn pull_upstream_event(&mut self) -> Result<gst::Event, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_pull_upstream_event(
-                self.0.as_ptr(),
-            ))
-            .ok_or_else(|| glib_bool_error!("Failed to pull event"))
+            Option::<_>::from_glib_full(ffi::gst_harness_pull_upstream_event(self.0.as_ptr()))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to pull event"))
         }
     }
 
     pub fn push(&mut self, buffer: gst::Buffer) -> Result<gst::FlowSuccess, gst::FlowError> {
-        let ret: gst::FlowReturn = unsafe {
-            from_glib(gst_check_sys::gst_harness_push(
-                self.0.as_ptr(),
-                buffer.into_ptr(),
-            ))
-        };
+        let ret: gst::FlowReturn =
+            unsafe { from_glib(ffi::gst_harness_push(self.0.as_ptr(), buffer.into_ptr())) };
         ret.into_result()
     }
 
     pub fn push_and_pull(&mut self, buffer: gst::Buffer) -> Result<gst::Buffer, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_push_and_pull(
+            Option::<_>::from_glib_full(ffi::gst_harness_push_and_pull(
                 self.0.as_ptr(),
                 buffer.into_ptr(),
             ))
-            .ok_or_else(|| glib_bool_error!("Failed to push and pull buffer"))
+            .ok_or_else(|| glib::glib_bool_error!("Failed to push and pull buffer"))
         }
     }
 
     pub fn push_event(&mut self, event: gst::Event) -> bool {
         unsafe {
-            from_glib(gst_check_sys::gst_harness_push_event(
+            from_glib(ffi::gst_harness_push_event(
                 self.0.as_ptr(),
                 event.into_ptr(),
             ))
@@ -320,19 +289,19 @@ impl Harness {
 
     pub fn push_from_src(&mut self) -> Result<gst::FlowSuccess, gst::FlowError> {
         let ret: gst::FlowReturn =
-            unsafe { from_glib(gst_check_sys::gst_harness_push_from_src(self.0.as_ptr())) };
+            unsafe { from_glib(ffi::gst_harness_push_from_src(self.0.as_ptr())) };
         ret.into_result()
     }
 
     pub fn push_to_sink(&mut self) -> Result<gst::FlowSuccess, gst::FlowError> {
         let ret: gst::FlowReturn =
-            unsafe { from_glib(gst_check_sys::gst_harness_push_to_sink(self.0.as_ptr())) };
+            unsafe { from_glib(ffi::gst_harness_push_to_sink(self.0.as_ptr())) };
         ret.into_result()
     }
 
     pub fn push_upstream_event(&mut self, event: gst::Event) -> bool {
         unsafe {
-            from_glib(gst_check_sys::gst_harness_push_upstream_event(
+            from_glib(ffi::gst_harness_push_upstream_event(
                 self.0.as_ptr(),
                 event.into_ptr(),
             ))
@@ -340,28 +309,28 @@ impl Harness {
     }
 
     pub fn query_latency(&self) -> gst::ClockTime {
-        unsafe { from_glib(gst_check_sys::gst_harness_query_latency(self.0.as_ptr())) }
+        unsafe { from_glib(ffi::gst_harness_query_latency(self.0.as_ptr())) }
     }
 
     //pub fn set(&mut self, element_name: &str, first_property_name: &str, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_set() }
+    //    unsafe { TODO: call ffi::gst_harness_set() }
     //}
 
     pub fn set_blocking_push_mode(&mut self) {
         unsafe {
-            gst_check_sys::gst_harness_set_blocking_push_mode(self.0.as_ptr());
+            ffi::gst_harness_set_blocking_push_mode(self.0.as_ptr());
         }
     }
 
     pub fn set_caps(&mut self, in_: gst::Caps, out: gst::Caps) {
         unsafe {
-            gst_check_sys::gst_harness_set_caps(self.0.as_ptr(), in_.into_ptr(), out.into_ptr());
+            ffi::gst_harness_set_caps(self.0.as_ptr(), in_.into_ptr(), out.into_ptr());
         }
     }
 
     pub fn set_caps_str(&mut self, in_: &str, out: &str) {
         unsafe {
-            gst_check_sys::gst_harness_set_caps_str(
+            ffi::gst_harness_set_caps_str(
                 self.0.as_ptr(),
                 in_.to_glib_none().0,
                 out.to_glib_none().0,
@@ -371,48 +340,48 @@ impl Harness {
 
     pub fn set_drop_buffers(&mut self, drop_buffers: bool) {
         unsafe {
-            gst_check_sys::gst_harness_set_drop_buffers(self.0.as_ptr(), drop_buffers.to_glib());
+            ffi::gst_harness_set_drop_buffers(self.0.as_ptr(), drop_buffers.to_glib());
         }
     }
 
     pub fn set_forwarding(&mut self, forwarding: bool) {
         unsafe {
-            gst_check_sys::gst_harness_set_forwarding(self.0.as_ptr(), forwarding.to_glib());
+            ffi::gst_harness_set_forwarding(self.0.as_ptr(), forwarding.to_glib());
         }
     }
 
     //pub fn set_propose_allocator<P: IsA<gst::Allocator>>(&mut self, allocator: Option<&P>, params: Option<&gst::AllocationParams>) {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_set_propose_allocator() }
+    //    unsafe { TODO: call ffi::gst_harness_set_propose_allocator() }
     //}
 
     pub fn set_sink_caps(&mut self, caps: gst::Caps) {
         unsafe {
-            gst_check_sys::gst_harness_set_sink_caps(self.0.as_ptr(), caps.into_ptr());
+            ffi::gst_harness_set_sink_caps(self.0.as_ptr(), caps.into_ptr());
         }
     }
 
     pub fn set_sink_caps_str(&mut self, str: &str) {
         unsafe {
-            gst_check_sys::gst_harness_set_sink_caps_str(self.0.as_ptr(), str.to_glib_none().0);
+            ffi::gst_harness_set_sink_caps_str(self.0.as_ptr(), str.to_glib_none().0);
         }
     }
 
     pub fn set_src_caps(&mut self, caps: gst::Caps) {
         unsafe {
-            gst_check_sys::gst_harness_set_src_caps(self.0.as_ptr(), caps.into_ptr());
+            ffi::gst_harness_set_src_caps(self.0.as_ptr(), caps.into_ptr());
         }
     }
 
     pub fn set_src_caps_str(&mut self, str: &str) {
         unsafe {
-            gst_check_sys::gst_harness_set_src_caps_str(self.0.as_ptr(), str.to_glib_none().0);
+            ffi::gst_harness_set_src_caps_str(self.0.as_ptr(), str.to_glib_none().0);
         }
     }
 
     pub fn set_time(&mut self, time: gst::ClockTime) -> Result<(), glib::BoolError> {
         unsafe {
-            glib_result_from_gboolean!(
-                gst_check_sys::gst_harness_set_time(self.0.as_ptr(), time.to_glib()),
+            glib::glib_result_from_gboolean!(
+                ffi::gst_harness_set_time(self.0.as_ptr(), time.to_glib()),
                 "Failed to set time",
             )
         }
@@ -420,13 +389,13 @@ impl Harness {
 
     pub fn set_upstream_latency(&mut self, latency: gst::ClockTime) {
         unsafe {
-            gst_check_sys::gst_harness_set_upstream_latency(self.0.as_ptr(), latency.to_glib());
+            ffi::gst_harness_set_upstream_latency(self.0.as_ptr(), latency.to_glib());
         }
     }
 
     pub fn sink_push_many(&mut self, pushes: u32) -> Result<gst::FlowSuccess, gst::FlowError> {
         let ret: gst::FlowReturn = unsafe {
-            from_glib(gst_check_sys::gst_harness_sink_push_many(
+            from_glib(ffi::gst_harness_sink_push_many(
                 self.0.as_ptr(),
                 pushes as i32,
             ))
@@ -440,7 +409,7 @@ impl Harness {
         pushes: u32,
     ) -> Result<gst::FlowSuccess, gst::FlowError> {
         let ret: gst::FlowReturn = unsafe {
-            from_glib(gst_check_sys::gst_harness_src_crank_and_push_many(
+            from_glib(ffi::gst_harness_src_crank_and_push_many(
                 self.0.as_ptr(),
                 cranks as i32,
                 pushes as i32,
@@ -450,57 +419,55 @@ impl Harness {
     }
 
     pub fn src_push_event(&mut self) -> bool {
-        unsafe { from_glib(gst_check_sys::gst_harness_src_push_event(self.0.as_ptr())) }
+        unsafe { from_glib(ffi::gst_harness_src_push_event(self.0.as_ptr())) }
     }
 
     //pub fn stress_custom_start<'a, P: Into<Option<&'a /*Ignored*/glib::Func>>, Q: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, init: P, callback: /*Unknown conversion*//*Unimplemented*/Func, data: Q, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_custom_start() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_custom_start() }
     //}
 
     //pub fn stress_property_start_full(&mut self, name: &str, value: /*Ignored*/&glib::Value, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_property_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_property_start_full() }
     //}
 
     //pub fn stress_push_buffer_start_full(&mut self, caps: &mut gst::Caps, segment: /*Ignored*/&gst::Segment, buf: &mut gst::Buffer, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_buffer_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_buffer_start_full() }
     //}
 
     //pub fn stress_push_buffer_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, caps: &mut gst::Caps, segment: /*Ignored*/&gst::Segment, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareBufferFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_buffer_with_cb_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_buffer_with_cb_start_full() }
     //}
 
     //pub fn stress_push_event_start_full(&mut self, event: &mut gst::Event, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_event_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_event_start_full() }
     //}
 
     //pub fn stress_push_event_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareEventFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_event_with_cb_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_event_with_cb_start_full() }
     //}
 
     //pub fn stress_push_upstream_event_start_full(&mut self, event: &mut gst::Event, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_upstream_event_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_upstream_event_start_full() }
     //}
 
     //pub fn stress_push_upstream_event_with_cb_start_full<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&mut self, func: /*Unknown conversion*//*Unimplemented*/HarnessPrepareEventFunc, data: P, notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_push_upstream_event_with_cb_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_push_upstream_event_with_cb_start_full() }
     //}
 
     //pub fn stress_requestpad_start_full(&mut self, templ: /*Ignored*/&gst::PadTemplate, name: &str, caps: &mut gst::Caps, release: bool, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_requestpad_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_requestpad_start_full() }
     //}
 
     //pub fn stress_statechange_start_full(&mut self, sleep: libc::c_ulong) -> /*Ignored*/Option<HarnessThread> {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_statechange_start_full() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_statechange_start_full() }
     //}
 
     #[cfg(any(feature = "v1_14", feature = "dox"))]
     #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_14")))]
     pub fn take_all_data_as_buffer(&mut self) -> Result<gst::Buffer, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_take_all_data_as_buffer(
-                self.0.as_ptr(),
-            ))
-            .ok_or_else(|| glib_bool_error!("Failed to take all data as buffer"))
+            Option::<_>::from_glib_full(ffi::gst_harness_take_all_data_as_buffer(self.0.as_ptr()))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to take all data as buffer"))
         }
     }
 
@@ -508,46 +475,40 @@ impl Harness {
     #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_14")))]
     pub fn take_all_data_as_bytes(&mut self) -> Result<glib::Bytes, glib::BoolError> {
         unsafe {
-            Option::<_>::from_glib_full(gst_check_sys::gst_harness_take_all_data_as_bytes(
-                self.0.as_ptr(),
-            ))
-            .ok_or_else(|| glib_bool_error!("Failed to take all data as bytes"))
+            Option::<_>::from_glib_full(ffi::gst_harness_take_all_data_as_bytes(self.0.as_ptr()))
+                .ok_or_else(|| glib::glib_bool_error!("Failed to take all data as bytes"))
         }
     }
 
     pub fn try_pull(&mut self) -> Option<gst::Buffer> {
-        unsafe { from_glib_full(gst_check_sys::gst_harness_try_pull(self.0.as_ptr())) }
+        unsafe { from_glib_full(ffi::gst_harness_try_pull(self.0.as_ptr())) }
     }
 
     pub fn try_pull_event(&mut self) -> Option<gst::Event> {
-        unsafe { from_glib_full(gst_check_sys::gst_harness_try_pull_event(self.0.as_ptr())) }
+        unsafe { from_glib_full(ffi::gst_harness_try_pull_event(self.0.as_ptr())) }
     }
 
     pub fn try_pull_upstream_event(&mut self) -> Option<gst::Event> {
-        unsafe {
-            from_glib_full(gst_check_sys::gst_harness_try_pull_upstream_event(
-                self.0.as_ptr(),
-            ))
-        }
+        unsafe { from_glib_full(ffi::gst_harness_try_pull_upstream_event(self.0.as_ptr())) }
     }
 
     pub fn upstream_events_in_queue(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_upstream_events_in_queue(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_upstream_events_in_queue(self.0.as_ptr()) }
     }
 
     pub fn upstream_events_received(&self) -> u32 {
-        unsafe { gst_check_sys::gst_harness_upstream_events_received(self.0.as_ptr()) }
+        unsafe { ffi::gst_harness_upstream_events_received(self.0.as_ptr()) }
     }
 
     pub fn use_systemclock(&mut self) {
         unsafe {
-            gst_check_sys::gst_harness_use_systemclock(self.0.as_ptr());
+            ffi::gst_harness_use_systemclock(self.0.as_ptr());
         }
     }
 
     pub fn use_testclock(&mut self) {
         unsafe {
-            gst_check_sys::gst_harness_use_testclock(self.0.as_ptr());
+            ffi::gst_harness_use_testclock(self.0.as_ptr());
         }
     }
 
@@ -557,14 +518,14 @@ impl Harness {
         timeout: u32,
     ) -> Result<(), glib::BoolError> {
         unsafe {
-            glib_result_from_gboolean!(
-                gst_check_sys::gst_harness_wait_for_clock_id_waits(self.0.as_ptr(), waits, timeout),
+            glib::glib_result_from_gboolean!(
+                ffi::gst_harness_wait_for_clock_id_waits(self.0.as_ptr(), waits, timeout),
                 "Failed to wait for clock id waits",
             )
         }
     }
 
-    unsafe fn from_glib_full(ptr: *mut gst_check_sys::GstHarness) -> Harness {
+    unsafe fn from_glib_full(ptr: *mut ffi::GstHarness) -> Harness {
         assert!(!ptr.is_null());
 
         Harness(ptr::NonNull::new_unchecked(ptr))
@@ -572,16 +533,12 @@ impl Harness {
 
     pub fn new(element_name: &str) -> Harness {
         assert_initialized_main_thread!();
-        unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new(
-                element_name.to_glib_none().0,
-            ))
-        }
+        unsafe { Self::from_glib_full(ffi::gst_harness_new(element_name.to_glib_none().0)) }
     }
 
     pub fn new_empty() -> Harness {
         assert_initialized_main_thread!();
-        unsafe { Self::from_glib_full(gst_check_sys::gst_harness_new_empty()) }
+        unsafe { Self::from_glib_full(ffi::gst_harness_new_empty()) }
     }
 
     pub fn new_full<P: IsA<gst::Element>>(
@@ -595,7 +552,7 @@ impl Harness {
         let element_sinkpad_name = element_sinkpad_name.to_glib_none();
         let element_srcpad_name = element_srcpad_name.to_glib_none();
         unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new_full(
+            Self::from_glib_full(ffi::gst_harness_new_full(
                 element.as_ref().to_glib_none().0,
                 hsrc.to_glib_none().0 as *mut _,
                 element_sinkpad_name.0,
@@ -607,11 +564,7 @@ impl Harness {
 
     pub fn new_parse(launchline: &str) -> Harness {
         assert_initialized_main_thread!();
-        unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new_parse(
-                launchline.to_glib_none().0,
-            ))
-        }
+        unsafe { Self::from_glib_full(ffi::gst_harness_new_parse(launchline.to_glib_none().0)) }
     }
 
     pub fn with_element<P: IsA<gst::Element>>(
@@ -623,7 +576,7 @@ impl Harness {
         let element_sinkpad_name = element_sinkpad_name.to_glib_none();
         let element_srcpad_name = element_srcpad_name.to_glib_none();
         unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new_with_element(
+            Self::from_glib_full(ffi::gst_harness_new_with_element(
                 element.as_ref().to_glib_none().0,
                 element_sinkpad_name.0,
                 element_srcpad_name.0,
@@ -640,7 +593,7 @@ impl Harness {
         let element_sinkpad_name = element_sinkpad_name.to_glib_none();
         let element_srcpad_name = element_srcpad_name.to_glib_none();
         unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new_with_padnames(
+            Self::from_glib_full(ffi::gst_harness_new_with_padnames(
                 element_name.to_glib_none().0,
                 element_sinkpad_name.0,
                 element_srcpad_name.0,
@@ -655,7 +608,7 @@ impl Harness {
     ) -> Harness {
         assert_initialized_main_thread!();
         unsafe {
-            Self::from_glib_full(gst_check_sys::gst_harness_new_with_templates(
+            Self::from_glib_full(ffi::gst_harness_new_with_templates(
                 element_name.to_glib_none().0,
                 hsrc.to_glib_none().0 as *mut _,
                 hsink.to_glib_none().0 as *mut _,
@@ -664,7 +617,7 @@ impl Harness {
     }
 
     //pub fn stress_thread_stop(t: /*Ignored*/&mut HarnessThread) -> u32 {
-    //    unsafe { TODO: call gst_check_sys::gst_harness_stress_thread_stop() }
+    //    unsafe { TODO: call ffi::gst_harness_stress_thread_stop() }
     //}
 
     pub fn get_element(&self) -> Option<gst::Element> {
@@ -677,8 +630,8 @@ impl Harness {
             }
 
             // Clear floating flag if it is set
-            if gobject_sys::g_object_is_floating(ptr as *mut _) != glib_sys::GFALSE {
-                gobject_sys::g_object_ref_sink(ptr as *mut _);
+            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
+                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
             }
 
             from_glib_none(ptr)
@@ -695,8 +648,8 @@ impl Harness {
             }
 
             // Clear floating flag if it is set
-            if gobject_sys::g_object_is_floating(ptr as *mut _) != glib_sys::GFALSE {
-                gobject_sys::g_object_ref_sink(ptr as *mut _);
+            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
+                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
             }
 
             from_glib_none(ptr)
@@ -713,8 +666,8 @@ impl Harness {
             }
 
             // Clear floating flag if it is set
-            if gobject_sys::g_object_is_floating(ptr as *mut _) != glib_sys::GFALSE {
-                gobject_sys::g_object_ref_sink(ptr as *mut _);
+            if glib::gobject_ffi::g_object_is_floating(ptr as *mut _) != glib::ffi::GFALSE {
+                glib::gobject_ffi::g_object_ref_sink(ptr as *mut _);
             }
 
             from_glib_none(ptr)
diff --git a/gstreamer-check/src/lib.rs b/gstreamer-check/src/lib.rs
index f6d89b6b4..ab44aff08 100644
--- a/gstreamer-check/src/lib.rs
+++ b/gstreamer-check/src/lib.rs
@@ -8,18 +8,11 @@
 
 #![cfg_attr(feature = "dox", feature(doc_cfg))]
 
-extern crate glib_sys;
-extern crate gobject_sys;
-extern crate gstreamer as gst;
-extern crate gstreamer_check_sys as gst_check_sys;
-extern crate gstreamer_sys as gst_sys;
-
-#[macro_use]
-extern crate glib;
+pub use ffi;
 
 macro_rules! assert_initialized_main_thread {
     () => {
-        if unsafe { ::gst_sys::gst_is_initialized() } != ::glib_sys::GTRUE {
+        if unsafe { gst::ffi::gst_is_initialized() } != glib::ffi::GTRUE {
             panic!("GStreamer has not been initialized. Call `gst::init` first.");
         }
     };
@@ -30,12 +23,12 @@ macro_rules! assert_initialized_main_thread {
 #[allow(clippy::match_same_arms)]
 #[allow(clippy::type_complexity)]
 mod auto;
-pub use auto::*;
+pub use crate::auto::*;
 
 mod test_clock;
 
 pub mod harness;
-pub use harness::Harness;
+pub use crate::harness::Harness;
 
 // Re-export all the traits in a prelude module, so that applications
 // can always "use gst::prelude::*" without getting conflicts
@@ -43,5 +36,5 @@ pub mod prelude {
     pub use glib::prelude::*;
     pub use gst::prelude::*;
 
-    pub use auto::traits::*;
+    pub use crate::auto::traits::*;
 }
diff --git a/gstreamer-check/src/test_clock.rs b/gstreamer-check/src/test_clock.rs
index 754021902..a7afc12d2 100644
--- a/gstreamer-check/src/test_clock.rs
+++ b/gstreamer-check/src/test_clock.rs
@@ -6,16 +6,14 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use crate::TestClock;
 use glib::translate::*;
-use gst;
-use gst_check_sys;
 use std::ptr;
-use TestClock;
 
 impl TestClock {
     pub fn has_id(&self, id: &gst::ClockId) -> bool {
         unsafe {
-            from_glib(gst_check_sys::gst_test_clock_has_id(
+            from_glib(ffi::gst_test_clock_has_id(
                 self.to_glib_none().0,
                 id.to_glib_none().0,
             ))
@@ -25,7 +23,7 @@ impl TestClock {
     pub fn peek_next_pending_id(&self) -> Option<gst::ClockId> {
         unsafe {
             let mut id = ptr::null_mut();
-            let ret: bool = from_glib(gst_check_sys::gst_test_clock_peek_next_pending_id(
+            let ret: bool = from_glib(ffi::gst_test_clock_peek_next_pending_id(
                 self.to_glib_none().0,
                 &mut id,
             ));
@@ -41,7 +39,7 @@ impl TestClock {
     #[cfg_attr(feature = "dox", doc(cfg(feature = "v1_18")))]
     pub fn process_id(&self, pending_id: &gst::ClockId) -> bool {
         unsafe {
-            from_glib(gst_check_sys::gst_test_clock_process_id(
+            from_glib(ffi::gst_test_clock_process_id(
                 self.to_glib_none().0,
                 pending_id.to_glib_none().0,
             ))
@@ -50,7 +48,7 @@ impl TestClock {
 
     pub fn process_id_list(&self, pending_list: &[&gst::ClockId]) -> u32 {
         unsafe {
-            gst_check_sys::gst_test_clock_process_id_list(
+            ffi::gst_test_clock_process_id_list(
                 self.to_glib_none().0,
                 pending_list.to_glib_none().0,
             )
@@ -59,7 +57,7 @@ impl TestClock {
 
     pub fn process_next_clock_id(&self) -> Option<gst::ClockId> {
         unsafe {
-            from_glib_full(gst_check_sys::gst_test_clock_process_next_clock_id(
+            from_glib_full(ffi::gst_test_clock_process_next_clock_id(
                 self.to_glib_none().0,
             ))
         }
@@ -68,7 +66,7 @@ impl TestClock {
     pub fn wait_for_multiple_pending_ids(&self, count: u32) -> Vec<gst::ClockId> {
         unsafe {
             let mut pending_list = ptr::null_mut();
-            gst_check_sys::gst_test_clock_wait_for_multiple_pending_ids(
+            ffi::gst_test_clock_wait_for_multiple_pending_ids(
                 self.to_glib_none().0,
                 count,
                 &mut pending_list,
@@ -80,7 +78,7 @@ impl TestClock {
     pub fn wait_for_next_pending_id(&self) -> gst::ClockId {
         unsafe {
             let mut id = ptr::null_mut();
-            gst_check_sys::gst_test_clock_wait_for_next_pending_id(self.to_glib_none().0, &mut id);
+            ffi::gst_test_clock_wait_for_next_pending_id(self.to_glib_none().0, &mut id);
             from_glib_full(id)
         }
     }
@@ -94,7 +92,7 @@ impl TestClock {
     ) -> (bool, Vec<gst::ClockId>) {
         unsafe {
             let mut pending_list = ptr::null_mut();
-            let res = gst_check_sys::gst_test_clock_timed_wait_for_multiple_pending_ids(
+            let res = ffi::gst_test_clock_timed_wait_for_multiple_pending_ids(
                 self.to_glib_none().0,
                 count,
                 timeout_ms,