diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index bed6d9c46029..366dcfef71bb 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -83,6 +83,15 @@ Non-comprehensive list of changes in this release
 New Compiler Flags
 ------------------
 
+- :option:`-ffp-cast-overflow-workaround` and
+  :option:`-fnofp-cast-overflow-workaround`
+  enable (disable) a workaround for code that casts floating-point values to
+  integers and back to floating-point. If the floating-point value is not
+  representable in the intermediate integer type, the code is incorrect
+  according to the language standard. This flag will attempt to generate code
+  as if the result of an overflowing conversion matches the overflowing behavior
+  of a target's native float-to-int conversion instructions.
+
 - ...
 
 Deprecated Compiler Flags