diff --git a/dlls/riched20/editor.c b/dlls/riched20/editor.c
index 9c54623c526..e74b7eed9f6 100644
--- a/dlls/riched20/editor.c
+++ b/dlls/riched20/editor.c
@@ -864,7 +864,7 @@ void ME_RTFParAttrHook(RTF_Info *info)
     info->fmt.wEffects |= PFE_RTLPARA;
     break;
   case rtfLTRPar:
-    info->fmt.dwMask = PFM_RTLPARA;
+    info->fmt.dwMask |= PFM_RTLPARA;
     info->fmt.wEffects &= ~PFE_RTLPARA;
     break;
   }