diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst
index fbcd1eff86ad0593fb5e4b8da5c46aee7d811eec..cf251d6b0d87c4d8e7a6e566edd050d8154855a1 100644
--- a/docs/ReleaseNotes.rst
+++ b/docs/ReleaseNotes.rst
@@ -128,6 +128,16 @@ getStorageClass now returns what is written it the source code for that decl.
 
 ...
 
+libclang
+--------
+
+The clang_CXCursorSet_contains() function previously incorrectly returned 0
+if it contained a CXCursor, contrary to what the documentation stated.  This
+has been fixed so that the function returns a non-zero value if the set
+contains a cursor.  This is API breaking change, but matches the intended
+original behavior.  Moreover, this also fixes the issue of an invalid CXCursorSet
+appearing to contain any CXCursor.
+
 Python Binding Changes
 ----------------------