diff --git a/toolkit/locales/l10n.mk b/toolkit/locales/l10n.mk
index 7b8e6338f11a..c70e07012fe2 100644
--- a/toolkit/locales/l10n.mk
+++ b/toolkit/locales/l10n.mk
@@ -103,7 +103,7 @@ else
 STAGEDIST = $(_ABS_DIST)/l10n-stage/$(MOZ_PKG_DIR)
 endif
 
-include $(topsrcdir)/toolkit/mozapps/installer/signing.mk
+include $(MOZILLA_DIR)/toolkit/mozapps/installer/signing.mk
 include $(MOZILLA_DIR)/toolkit/mozapps/installer/packager.mk
 
 $(STAGEDIST): AB_CD:=en-US
diff --git a/toolkit/mozapps/installer/windows/nsis/makensis.mk b/toolkit/mozapps/installer/windows/nsis/makensis.mk
index 2b59ab3ff91a..fb87635aa4ca 100644
--- a/toolkit/mozapps/installer/windows/nsis/makensis.mk
+++ b/toolkit/mozapps/installer/windows/nsis/makensis.mk
@@ -41,7 +41,7 @@ ifndef CONFIG_DIR
 $(error CONFIG_DIR must be set before including makensis.mk)
 endif
 
-include $(topsrcdir)/toolkit/mozapps/installer/signing.mk
+include $(MOZILLA_DIR)/toolkit/mozapps/installer/signing.mk
 
 ABS_CONFIG_DIR := $(shell pwd)/$(CONFIG_DIR)