diff --git a/config/mozBDate.pm b/config/mozBDate.pm
index 56d7f3b3e0bd..cbb89700cbc8 100755
--- a/config/mozBDate.pm
+++ b/config/mozBDate.pm
@@ -126,11 +126,11 @@ sub SubstituteBuildNumber($$$) {
     }
     elsif ($id =~ "GRE_BUILD_ID") {
 	if (defined($ENV{'MOZ_MILESTONE_RELEASE'})) {
-	    $temp = "GRE_BUILD_ID " . $milestone;
+	    $temp = "GRE_BUILD_ID \"$milestone\"";
 	} else {
-	    $temp = "GRE_BUILD_ID " . "${milestone}_${build}";
+	    $temp = "GRE_BUILD_ID \"${milestone}_${build}\"";
 	}
-        $id =~ s/GRE_BUILD_ID\s\d+/$temp/;
+        $id =~ s/GRE_BUILD_ID\s\"\d+\"/$temp/;
         print $OUTFILE $id;
     }
     else {
diff --git a/config/nsBuildID.h.in b/config/nsBuildID.h.in
index afde5e17b421..4f894cfad3c0 100644
--- a/config/nsBuildID.h.in
+++ b/config/nsBuildID.h.in
@@ -17,7 +17,7 @@
  * GRE_BUILD_ID will just contain <milestone>. 
  *
  */
-#define GRE_BUILD_ID 00000000000
+#define GRE_BUILD_ID "00000000000"
 
 #endif /* _NSBUILDID_H_ */