diff -up firefox-42.0/browser/installer/package-manifest.in.debug firefox-42.0/browser/installer/package-manifest.in
--- firefox-42.0/browser/installer/package-manifest.in.debug	2015-10-30 15:35:53.231857572 +0100
+++ firefox-42.0/browser/installer/package-manifest.in	2015-10-30 15:36:58.975091068 +0100
@@ -620,7 +620,7 @@
 @RESPATH@/components/MozKeyboard.js
 @RESPATH@/components/InputMethod.manifest
 
-#ifdef MOZ_DEBUG
+#ifdef ENABLE_TESTS
 @RESPATH@/components/TestInterfaceJS.js
 @RESPATH@/components/TestInterfaceJS.manifest
 @RESPATH@/components/TestInterfaceJSMaplike.js