diff --git a/gstreamer-base/src/subclass/aggregator.rs b/gstreamer-base/src/subclass/aggregator.rs
index 352d23bbb..07223a8db 100644
--- a/gstreamer-base/src/subclass/aggregator.rs
+++ b/gstreamer-base/src/subclass/aggregator.rs
@@ -88,11 +88,11 @@ pub trait AggregatorImpl: ElementImpl + Send + Sync + 'static {
         timeout: bool,
     ) -> Result<gst::FlowSuccess, gst::FlowError>;
 
-    fn start(&self, aggregator: &Aggregator) -> bool {
+    fn start(&self, aggregator: &Aggregator) -> Result<(), gst::ErrorMessage> {
         self.parent_start(aggregator)
     }
 
-    fn stop(&self, aggregator: &Aggregator) -> bool {
+    fn stop(&self, aggregator: &Aggregator) -> Result<(), gst::ErrorMessage> {
         self.parent_stop(aggregator)
     }
 
@@ -287,25 +287,45 @@ pub trait AggregatorImpl: ElementImpl + Send + Sync + 'static {
         }
     }
 
-    fn parent_start(&self, aggregator: &Aggregator) -> bool {
+    fn parent_start(&self, aggregator: &Aggregator) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = self.get_type_data();
             let parent_class = data.as_ref().get_parent_class() as *mut ffi::GstAggregatorClass;
-            (*parent_class)
-                .start
-                .map(|f| from_glib(f(aggregator.to_glib_none().0)))
-                .unwrap_or(false)
+            let f = (*parent_class).start.ok_or_else(|| {
+                gst_error_msg!(
+                    gst::CoreError::Failed,
+                    ["Parent function `start` is not defined"]
+                )
+            })?;
+            if from_glib(f(aggregator.to_glib_none().0)) {
+                Ok(())
+            } else {
+                Err(gst_error_msg!(
+                    gst::CoreError::Failed,
+                    ["Parent function `start` failed"]
+                ))
+            }
         }
     }
 
-    fn parent_stop(&self, aggregator: &Aggregator) -> bool {
+    fn parent_stop(&self, aggregator: &Aggregator) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = self.get_type_data();
             let parent_class = data.as_ref().get_parent_class() as *mut ffi::GstAggregatorClass;
-            (*parent_class)
-                .stop
-                .map(|f| from_glib(f(aggregator.to_glib_none().0)))
-                .unwrap_or(false)
+            let f = (*parent_class).stop.ok_or_else(|| {
+                gst_error_msg!(
+                    gst::CoreError::Failed,
+                    ["Parent function `stop` is not defined"]
+                )
+            })?;
+            if from_glib(f(aggregator.to_glib_none().0)) {
+                Ok(())
+            } else {
+                Err(gst_error_msg!(
+                    gst::CoreError::Failed,
+                    ["Parent function `stop` failed"]
+                ))
+            }
         }
     }
 
@@ -635,7 +655,16 @@ where
     let imp = instance.get_impl();
     let wrap: Aggregator = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.start(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.start(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn aggregator_stop<T: ObjectSubclass>(
@@ -650,7 +679,16 @@ where
     let imp = instance.get_impl();
     let wrap: Aggregator = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.stop(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn aggregator_get_next_time<T: ObjectSubclass>(
diff --git a/gstreamer-base/src/subclass/base_sink.rs b/gstreamer-base/src/subclass/base_sink.rs
index acf6fafc5..ad60ddb36 100644
--- a/gstreamer-base/src/subclass/base_sink.rs
+++ b/gstreamer-base/src/subclass/base_sink.rs
@@ -23,12 +23,12 @@ use BaseSink;
 use BaseSinkClass;
 
 pub trait BaseSinkImpl: ElementImpl + Send + Sync + 'static {
-    fn start(&self, _element: &BaseSink) -> bool {
-        true
+    fn start(&self, _element: &BaseSink) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
-    fn stop(&self, _element: &BaseSink) -> bool {
-        true
+    fn stop(&self, _element: &BaseSink) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
     fn render(
@@ -87,12 +87,12 @@ pub trait BaseSinkImpl: ElementImpl + Send + Sync + 'static {
         self.parent_fixate(element, caps)
     }
 
-    fn unlock(&self, _element: &BaseSink) -> bool {
-        true
+    fn unlock(&self, _element: &BaseSink) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
-    fn unlock_stop(&self, _element: &BaseSink) -> bool {
-        true
+    fn unlock_stop(&self, _element: &BaseSink) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
     fn parent_query(&self, element: &BaseSink, query: &mut gst::QueryRef) -> bool {
@@ -207,7 +207,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSink = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.start(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.start(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_sink_stop<T: ObjectSubclass>(
@@ -222,7 +231,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSink = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.stop(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_sink_render<T: ObjectSubclass>(
@@ -427,7 +445,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSink = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.unlock(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.unlock(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_sink_unlock_stop<T: ObjectSubclass>(
@@ -443,7 +470,13 @@ where
     let wrap: BaseSink = from_glib_borrow(ptr);
 
     gst_panic_to_error!(&wrap, &instance.panicked(), false, {
-        imp.unlock_stop(&wrap)
+        match imp.unlock_stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
     })
     .to_glib()
 }
diff --git a/gstreamer-base/src/subclass/base_src.rs b/gstreamer-base/src/subclass/base_src.rs
index e2ff94d05..cf29864f6 100644
--- a/gstreamer-base/src/subclass/base_src.rs
+++ b/gstreamer-base/src/subclass/base_src.rs
@@ -23,12 +23,12 @@ use BaseSrc;
 use BaseSrcClass;
 
 pub trait BaseSrcImpl: ElementImpl + Send + Sync + 'static {
-    fn start(&self, _element: &BaseSrc) -> bool {
-        true
+    fn start(&self, _element: &BaseSrc) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
-    fn stop(&self, _element: &BaseSrc) -> bool {
-        true
+    fn stop(&self, _element: &BaseSrc) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
     fn is_seekable(&self, _element: &BaseSrc) -> bool {
@@ -86,12 +86,12 @@ pub trait BaseSrcImpl: ElementImpl + Send + Sync + 'static {
         self.parent_fixate(element, caps)
     }
 
-    fn unlock(&self, _element: &BaseSrc) -> bool {
-        true
+    fn unlock(&self, _element: &BaseSrc) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
-    fn unlock_stop(&self, _element: &BaseSrc) -> bool {
-        true
+    fn unlock_stop(&self, _element: &BaseSrc) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
     fn parent_create(
@@ -259,7 +259,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSrc = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.start(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.start(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_src_stop<T: ObjectSubclass>(
@@ -274,7 +283,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSrc = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.stop(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_src_is_seekable<T: ObjectSubclass>(
@@ -537,7 +555,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseSrc = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.unlock(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.unlock(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_src_unlock_stop<T: ObjectSubclass>(
@@ -553,7 +580,13 @@ where
     let wrap: BaseSrc = from_glib_borrow(ptr);
 
     gst_panic_to_error!(&wrap, &instance.panicked(), false, {
-        imp.unlock_stop(&wrap)
+        match imp.unlock_stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
     })
     .to_glib()
 }
diff --git a/gstreamer-base/src/subclass/base_transform.rs b/gstreamer-base/src/subclass/base_transform.rs
index d4ba53570..c88038c2d 100644
--- a/gstreamer-base/src/subclass/base_transform.rs
+++ b/gstreamer-base/src/subclass/base_transform.rs
@@ -21,12 +21,12 @@ use BaseTransform;
 use BaseTransformClass;
 
 pub trait BaseTransformImpl: ElementImpl + Send + Sync + 'static {
-    fn start(&self, _element: &BaseTransform) -> bool {
-        true
+    fn start(&self, _element: &BaseTransform) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
-    fn stop(&self, _element: &BaseTransform) -> bool {
-        true
+    fn stop(&self, _element: &BaseTransform) -> Result<(), gst::ErrorMessage> {
+        Ok(())
     }
 
     fn transform_caps(
@@ -349,7 +349,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseTransform = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.start(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.start(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_transform_stop<T: ObjectSubclass>(
@@ -364,7 +373,16 @@ where
     let imp = instance.get_impl();
     let wrap: BaseTransform = from_glib_borrow(ptr);
 
-    gst_panic_to_error!(&wrap, &instance.panicked(), false, { imp.stop(&wrap) }).to_glib()
+    gst_panic_to_error!(&wrap, &instance.panicked(), false, {
+        match imp.stop(&wrap) {
+            Ok(()) => true,
+            Err(err) => {
+                wrap.post_error_message(&err);
+                false
+            }
+        }
+    })
+    .to_glib()
 }
 
 unsafe extern "C" fn base_transform_transform_caps<T: ObjectSubclass>(