diff --git a/gstreamer-base/src/adapter.rs b/gstreamer-base/src/adapter.rs
index 0fdfaa394..2e3ecac8f 100644
--- a/gstreamer-base/src/adapter.rs
+++ b/gstreamer-base/src/adapter.rs
@@ -183,15 +183,15 @@ impl UniqueAdapter {
         self.0.push(buf);
     }
 
-    pub fn map(&mut self, nbytes: usize) -> Option<UniqueAdapterMap> {
+    pub fn map(&mut self, nbytes: usize) -> Result<UniqueAdapterMap, glib::error::BoolError> {
         use std::slice;
 
         unsafe {
             let ptr = gst_base_sys::gst_adapter_map(self.0.to_glib_none().0, nbytes);
             if ptr.is_null() {
-                None
+                Err(glib_bool_error!("size bytes are not available"))
             } else {
-                Some(UniqueAdapterMap(
+                Ok(UniqueAdapterMap(
                     self,
                     slice::from_raw_parts(ptr as *const u8, nbytes),
                 ))
diff --git a/gstreamer-base/src/functions.rs b/gstreamer-base/src/functions.rs
index e2a3186b8..c6f55cfe0 100644
--- a/gstreamer-base/src/functions.rs
+++ b/gstreamer-base/src/functions.rs
@@ -15,7 +15,7 @@ use std::mem;
 pub fn type_find_helper_for_data<P: IsA<gst::Object>, R: AsRef<[u8]>>(
     obj: Option<&P>,
     data: R,
-) -> Option<(gst::Caps, gst::TypeFindProbability)> {
+) -> Result<(gst::Caps, gst::TypeFindProbability), glib::error::BoolError> {
     assert_initialized_main_thread!();
     unsafe {
         let mut prob = mem::MaybeUninit::uninit();
@@ -28,9 +28,9 @@ pub fn type_find_helper_for_data<P: IsA<gst::Object>, R: AsRef<[u8]>>(
             prob.as_mut_ptr(),
         );
         if ret.is_null() {
-            None
+            Err(glib_bool_error!("No type could be found"))
         } else {
-            Some((from_glib_full(ret), from_glib(prob.assume_init())))
+            Ok((from_glib_full(ret), from_glib(prob.assume_init())))
         }
     }
 }
@@ -40,7 +40,7 @@ pub fn type_find_helper_for_data_with_extension<P: IsA<gst::Object>, R: AsRef<[u
     obj: Option<&P>,
     data: R,
     extension: Option<&str>,
-) -> Option<(gst::Caps, gst::TypeFindProbability)> {
+) -> Result<(gst::Caps, gst::TypeFindProbability), glib::error::BoolError> {
     assert_initialized_main_thread!();
     unsafe {
         let mut prob = mem::MaybeUninit::uninit();
@@ -54,9 +54,9 @@ pub fn type_find_helper_for_data_with_extension<P: IsA<gst::Object>, R: AsRef<[u
             prob.as_mut_ptr(),
         );
         if ret.is_null() {
-            None
+            Err(glib_bool_error!("No type could be found"))
         } else {
-            Some((from_glib_full(ret), from_glib(prob.assume_init())))
+            Ok((from_glib_full(ret), from_glib(prob.assume_init())))
         }
     }
 }
@@ -64,7 +64,7 @@ pub fn type_find_helper_for_data_with_extension<P: IsA<gst::Object>, R: AsRef<[u
 pub fn type_find_helper_for_buffer<P: IsA<gst::Object>>(
     obj: Option<&P>,
     buf: &gst::Buffer,
-) -> Option<(gst::Caps, gst::TypeFindProbability)> {
+) -> Result<(gst::Caps, gst::TypeFindProbability), glib::error::BoolError> {
     assert_initialized_main_thread!();
     unsafe {
         let mut prob = mem::MaybeUninit::uninit();
@@ -74,9 +74,9 @@ pub fn type_find_helper_for_buffer<P: IsA<gst::Object>>(
             prob.as_mut_ptr(),
         );
         if ret.is_null() {
-            None
+            Err(glib_bool_error!("No type could be found"))
         } else {
-            Some((from_glib_full(ret), from_glib(prob.assume_init())))
+            Ok((from_glib_full(ret), from_glib(prob.assume_init())))
         }
     }
 }
@@ -86,7 +86,7 @@ pub fn type_find_helper_for_buffer_with_extension<P: IsA<gst::Object>>(
     obj: Option<&P>,
     buf: &gst::Buffer,
     extension: Option<&str>,
-) -> Option<(gst::Caps, gst::TypeFindProbability)> {
+) -> Result<(gst::Caps, gst::TypeFindProbability), glib::error::BoolError> {
     assert_initialized_main_thread!();
     unsafe {
         let mut prob = mem::MaybeUninit::uninit();
@@ -97,9 +97,9 @@ pub fn type_find_helper_for_buffer_with_extension<P: IsA<gst::Object>>(
             prob.as_mut_ptr(),
         );
         if ret.is_null() {
-            None
+            Err(glib_bool_error!("No type could be found"))
         } else {
-            Some((from_glib_full(ret), from_glib(prob.assume_init())))
+            Ok((from_glib_full(ret), from_glib(prob.assume_init())))
         }
     }
 }
diff --git a/gstreamer-video/src/video_info.rs b/gstreamer-video/src/video_info.rs
index ebaa91cf1..88b79a5e0 100644
--- a/gstreamer-video/src/video_info.rs
+++ b/gstreamer-video/src/video_info.rs
@@ -147,9 +147,9 @@ impl PartialEq for VideoColorimetry {
 impl Eq for VideoColorimetry {}
 
 impl str::FromStr for ::VideoColorimetry {
-    type Err = ();
+    type Err = glib::error::BoolError;
 
-    fn from_str(s: &str) -> Result<Self, ()> {
+    fn from_str(s: &str) -> Result<Self, glib::error::BoolError> {
         assert_initialized_main_thread!();
 
         unsafe {
@@ -161,7 +161,7 @@ impl str::FromStr for ::VideoColorimetry {
             if valid {
                 Ok(VideoColorimetry(colorimetry.assume_init()))
             } else {
-                Err(())
+                Err(glib_bool_error!("Invalid colorimetry info"))
             }
         }
     }
@@ -834,9 +834,9 @@ impl ::VideoFieldOrder {
 
 #[cfg(any(feature = "v1_12", feature = "dox"))]
 impl str::FromStr for ::VideoFieldOrder {
-    type Err = ();
+    type Err = glib::error::BoolError;
 
-    fn from_str(s: &str) -> Result<Self, ()> {
+    fn from_str(s: &str) -> Result<Self, glib::error::BoolError> {
         assert_initialized_main_thread!();
 
         unsafe {
@@ -867,9 +867,9 @@ impl ::VideoInterlaceMode {
 }
 
 impl str::FromStr for ::VideoInterlaceMode {
-    type Err = ();
+    type Err = glib::error::BoolError;
 
-    fn from_str(s: &str) -> Result<Self, ()> {
+    fn from_str(s: &str) -> Result<Self, glib::error::BoolError> {
         assert_initialized_main_thread!();
 
         unsafe {