diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index d27d45d41015..5e14a95a212a 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -2663,7 +2663,8 @@ CSS_PROP_DISPLAY(
     Opacity,
     CSS_PROPERTY_PARSE_VALUE |
         CSS_PROPERTY_APPLIES_TO_PLACEHOLDER |
-        CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR,
+        CSS_PROPERTY_CAN_ANIMATE_ON_COMPOSITOR |
+        CSS_PROPERTY_CREATES_STACKING_CONTEXT,
     "",
     VARIANT_HN,
     nullptr,