diff --git a/locales/Makefile.in b/locales/Makefile.in
--- a/locales/Makefile.in
+++ b/locales/Makefile.in
@@ -39,17 +39,17 @@ DIST_FILES             = generic/install
 XULAPP_DEFINES = \
     $(DEFINES) \
     $(ACDEFINES) \
     -I$(call EXPAND_LOCALE_SRCDIR,toolkit/locales)/defines.inc \
     -I$(LOCALE_SRCDIR)/defines.inc \
     $(NULL)
 endif
 
-DEFINES += -DINSTALL_EXTENSION_ID=$("INSTALL_EXTENSION_ID")
+DEFINES += -DINSTALL_EXTENSION_ID="$(INSTALL_EXTENSION_ID)"
 DEFINES += -DCHATZILLA_VERSION=$(CHATZILLA_VERSION)
 DEFINES += -DCHATZILLA_BASE_VERSION=$(CHATZILLA_BASE_VERSION)
 
 include $(topsrcdir)/config/rules.mk
 
 ifneq (en-US,$(AB_CD))
 libs realchrome::
 	@echo "Comparing $(AB_CD) to en-US"