diff --git a/make/defs.mk b/make/defs.mk
index f72f079c..126d651a 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -82,11 +82,11 @@ export REENTRANT
 USE_CFG_XXX_MK        ?= true
 ifeq ($(USE_CFG_XXX_MK),true)
 ifeq ($(DEVELOPMENT),true)
-	include $(MODDIR)/make/defs-dev.mk
-	include $(TOPDIR)/make/cfg_dev.mk
+	-include $(MODDIR)/make/defs-dev.mk
+	-include $(TOPDIR)/make/cfg_dev.mk
 else
-	include $(MODDIR)/make/defs-dist.mk
-	include $(TOPDIR)/make/cfg_dist.mk
+	-include $(MODDIR)/make/defs-dist.mk
+	-include $(TOPDIR)/make/cfg_dist.mk
 endif
 endif