diff --git a/mozilla/dom/src/base/nsGlobalWindow.h b/mozilla/dom/src/base/nsGlobalWindow.h
index 9ac7162f92a..8546698d5eb 100644
--- a/mozilla/dom/src/base/nsGlobalWindow.h
+++ b/mozilla/dom/src/base/nsGlobalWindow.h
@@ -374,7 +374,7 @@ struct nsTimeoutImpl
   {
 #ifdef DEBUG_jst
     {
-      extern gTimeoutCnt;
+      extern PRInt32 gTimeoutCnt;
 
       ++gTimeoutCnt;
     }
@@ -389,7 +389,7 @@ struct nsTimeoutImpl
   {
 #ifdef DEBUG_jst
     {
-      extern gTimeoutCnt;
+      extern PRInt32 gTimeoutCnt;
 
       --gTimeoutCnt;
     }