1 files changed, 2 insertions, 2 deletions
diff --git a/toolkit/mozapps/extensions/internal/XPIProvider.jsm b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
index 2f298a934..600ec2ff5 100644
--- a/toolkit/mozapps/extensions/internal/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
@@ -6472,8 +6472,8 @@ AddonInternal.prototype = {
     }
     else if (app.id == FIREFOX_ID) {
      version = FIREFOX_APPCOMPATVERSION;
-      if (this.type != "extension")
-        //Only allow extensions in Firefox compatibility mode
+      if (this.type == "locale")
+        //Never allow language packs in Firefox compatibility mode
         return false;
 #endif
     }