--- a/b2g/installer/Makefile.in
+++ b/b2g/installer/Makefile.in
@@ -52,18 +52,20 @@ endif
 endif
 
 include $(topsrcdir)/toolkit/mozapps/installer/packager.mk
 
 # Note that JS_BINARY can be defined in packager.mk, so this test must come after
 # including that file. MOZ_PACKAGER_MINIFY_JS is used in packager.mk, but since
 # recipe evaluation is deferred, we can set it here after the inclusion.
 ifneq (,$(JS_BINARY))
+ifndef MOZ_DEBUG
 MOZ_PACKAGER_MINIFY_JS=1
 endif
+endif
 
 ifeq (bundle, $(MOZ_FS_LAYOUT))
 BINPATH = $(_BINPATH)
 DEFINES += -DAPPNAME=$(_APPNAME)
 else
 # Every other platform just winds up in dist/bin
 BINPATH = bin
 endif