diff --git a/CLOBBER b/CLOBBER
index f04b62fe514..e0e95faab14 100644
--- a/CLOBBER
+++ b/CLOBBER
@@ -22,4 +22,4 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Bug 870366 - Blacklisting PREF_JS_EXPORTS in Makefile.ins (because of 852814)
+Bug 1109248 - This needed a CLOBBER on Windows and OSX.
diff --git a/config/baseconfig.mk b/config/baseconfig.mk
index dd4af0d901e..d4d8081c5b0 100644
--- a/config/baseconfig.mk
+++ b/config/baseconfig.mk
@@ -90,7 +90,6 @@ _MOZBUILD_EXTERNAL_VARIABLES := \
   NO_DIST_INSTALL \
   OS_LIBS \
   PARALLEL_DIRS \
-  PREF_JS_EXPORTS \
   PROGRAM \
   PYTHON_UNIT_TESTS \
   RESOURCE_FILES \