diff --git a/gstreamer-rtsp-server/src/rtsp_session_pool.rs b/gstreamer-rtsp-server/src/rtsp_session_pool.rs
index c6e0b7240..b67a45cc1 100644
--- a/gstreamer-rtsp-server/src/rtsp_session_pool.rs
+++ b/gstreamer-rtsp-server/src/rtsp_session_pool.rs
@@ -48,9 +48,9 @@ pub trait RTSPSessionPoolExtManual: IsA<RTSPSessionPool> + 'static {
             glib::ffi::g_source_set_callback(
                 source,
                 Some(transmute::<
-                    *const (),
+                    *mut (),
                     unsafe extern "C" fn(glib::ffi::gpointer) -> i32,
-                >(trampoline_watch::<F> as *const ())),
+                >(trampoline_watch::<F> as *mut ())),
                 into_raw_watch(func),
                 Some(destroy_closure_watch::<F>),
             );
diff --git a/gstreamer/src/buffer.rs b/gstreamer/src/buffer.rs
index 846c4eb50..b2ddbc4bc 100644
--- a/gstreamer/src/buffer.rs
+++ b/gstreamer/src/buffer.rs
@@ -599,12 +599,13 @@ impl BufferRef {
         }
 
         unsafe {
-            let func_ptr: &F = &func;
+            let mut func = func;
+            let func_ptr: &mut F = &mut func;
 
             from_glib(ffi::gst_buffer_foreach_meta(
                 mut_override(self.as_ptr()),
                 Some(trampoline::<F>),
-                func_ptr as *const _ as *mut _,
+                func_ptr as *mut _ as *mut _,
             ))
         }
     }
@@ -643,12 +644,13 @@ impl BufferRef {
         }
 
         unsafe {
-            let func_ptr: &F = &func;
+            let mut func = func;
+            let func_ptr: &mut F = &mut func;
 
             from_glib(ffi::gst_buffer_foreach_meta(
                 mut_override(self.as_ptr()),
                 Some(trampoline::<F>),
-                func_ptr as *const _ as *mut _,
+                func_ptr as *mut _ as *mut _,
             ))
         }
     }
diff --git a/gstreamer/src/bufferlist.rs b/gstreamer/src/bufferlist.rs
index 9aa93fd35..e96e388a7 100644
--- a/gstreamer/src/bufferlist.rs
+++ b/gstreamer/src/bufferlist.rs
@@ -149,12 +149,13 @@ impl BufferListRef {
         }
 
         unsafe {
-            let func_ptr: &F = &func;
+            let mut func = func;
+            let func_ptr: &mut F = &mut func;
 
             from_glib(ffi::gst_buffer_list_foreach(
                 self.as_ptr() as *mut _,
                 Some(trampoline::<F>),
-                func_ptr as *const _ as *mut _,
+                func_ptr as *mut _ as *mut _,
             ))
         }
     }
@@ -198,12 +199,13 @@ impl BufferListRef {
         }
 
         unsafe {
-            let func_ptr: &F = &func;
+            let mut func = func;
+            let func_ptr: &mut F = &mut func;
 
             from_glib(ffi::gst_buffer_list_foreach(
                 self.as_ptr() as *mut _,
                 Some(trampoline::<F>),
-                func_ptr as *const _ as *mut _,
+                func_ptr as *mut _ as *mut _,
             ))
         }
     }
diff --git a/gstreamer/src/bus.rs b/gstreamer/src/bus.rs
index 7b1d94b02..c0eb90d8e 100644
--- a/gstreamer/src/bus.rs
+++ b/gstreamer/src/bus.rs
@@ -120,9 +120,9 @@ impl Bus {
             glib::ffi::g_source_set_callback(
                 source,
                 Some(transmute::<
-                    *const (),
+                    *mut (),
                     unsafe extern "C" fn(glib::ffi::gpointer) -> i32,
-                >(trampoline_watch::<F> as *const ())),
+                >(trampoline_watch::<F> as *mut ())),
                 into_raw_watch(func),
                 Some(destroy_closure_watch::<F>),
             );
diff --git a/gstreamer/src/registry.rs b/gstreamer/src/registry.rs
index 826e8d4fa..148747444 100644
--- a/gstreamer/src/registry.rs
+++ b/gstreamer/src/registry.rs
@@ -16,7 +16,7 @@ impl Registry {
         filter: P,
         first: bool,
     ) -> glib::List<PluginFeature> {
-        let filter_data: P = filter;
+        let mut filter_data: P = filter;
         unsafe extern "C" fn filter_func<P: FnMut(&PluginFeature) -> bool>(
             feature: *mut ffi::GstPluginFeature,
             user_data: glib::ffi::gpointer,
@@ -27,13 +27,13 @@ impl Registry {
             res.into_glib()
         }
         let filter = Some(filter_func::<P> as _);
-        let super_callback0: &P = &filter_data;
+        let super_callback0: &mut P = &mut filter_data;
         unsafe {
             FromGlibPtrContainer::from_glib_full(ffi::gst_registry_feature_filter(
                 self.to_glib_none().0,
                 filter,
                 first.into_glib(),
-                super_callback0 as *const _ as *mut _,
+                super_callback0 as *mut _ as *mut _,
             ))
         }
     }
@@ -76,24 +76,24 @@ impl Registry {
         filter: P,
         first: bool,
     ) -> glib::List<Plugin> {
-        let filter_data: P = filter;
+        let mut filter_data: P = filter;
         unsafe extern "C" fn filter_func<P: FnMut(&Plugin) -> bool>(
             plugin: *mut ffi::GstPlugin,
             user_data: glib::ffi::gpointer,
         ) -> glib::ffi::gboolean {
             let plugin = from_glib_borrow(plugin);
-            let callback = user_data as *const _ as *mut P;
+            let callback = user_data as *mut P;
             let res = (*callback)(&plugin);
             res.into_glib()
         }
         let filter = Some(filter_func::<P> as _);
-        let super_callback0: &P = &filter_data;
+        let super_callback0: &mut P = &mut filter_data;
         unsafe {
             FromGlibPtrContainer::from_glib_full(ffi::gst_registry_plugin_filter(
                 self.to_glib_none().0,
                 filter,
                 first.into_glib(),
-                super_callback0 as *const _ as *mut _,
+                super_callback0 as *mut _ as *mut _,
             ))
         }
     }