diff --git a/Makefile.am b/Makefile.am
index a04b95ae3..e26508ad9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -803,6 +803,7 @@ HFLAGS = \
 	-fwarn-tabs \
 	-optP-include -optP$(HASKELL_PACKAGE_VERSIONS_FILE) \
 	-hide-all-packages \
+	$(HCFLAGS) \
 	`cat $(HASKELL_PACKAGE_IDS_FILE)` \
 	$(GHC_BYVERSION_FLAGS)
 if DEVELOPER_MODE