diff --git a/gstreamer/src/miniobject.rs b/gstreamer/src/miniobject.rs
index 90954588e..d0c65c6df 100644
--- a/gstreamer/src/miniobject.rs
+++ b/gstreamer/src/miniobject.rs
@@ -34,7 +34,7 @@ impl<T: MiniObject> GstRc<T> {
         ffi::gst_mini_object_ref(ptr as *mut ffi::GstMiniObject);
 
         GstRc {
-            obj: T::from_mut_ptr(ptr as *mut T::GstType) as *mut T,
+            obj: ptr as *mut T::GstType as *mut T,
             borrowed: false,
             phantom: PhantomData,
         }
@@ -44,7 +44,7 @@ impl<T: MiniObject> GstRc<T> {
         assert!(!ptr.is_null());
 
         GstRc {
-            obj: T::from_mut_ptr(ptr as *mut T::GstType) as *mut T,
+            obj: ptr as *mut T::GstType as *mut T,
             borrowed: false,
             phantom: PhantomData,
         }
@@ -54,7 +54,7 @@ impl<T: MiniObject> GstRc<T> {
         assert!(!ptr.is_null());
 
         GstRc {
-            obj: T::from_mut_ptr(ptr as *mut T::GstType) as *mut T,
+            obj: ptr as *mut T::GstType as *mut T,
             borrowed: true,
             phantom: PhantomData,
         }
@@ -186,6 +186,7 @@ where
 
     unsafe fn from_mut_ptr<'a>(ptr: *mut Self::GstType) -> &'a mut Self {
         assert!(!ptr.is_null());
+        assert_ne!(ffi::gst_mini_object_is_writable(ptr as *mut ffi::GstMiniObject), glib_ffi::GFALSE);
         &mut *(ptr as *mut Self)
     }