diff --git a/Makefile b/Makefile
index a55a1e4e6cdaabd50c15c58e820a405be2ce88f8..7a95f4f8ef144559be32c4a7f7e89f7cbb9371f0 100644
--- a/Makefile
+++ b/Makefile
@@ -137,7 +137,7 @@ objtree		:= $(CURDIR)
 src		:= $(srctree)
 obj		:= $(objtree)
 
-VPATH		:= $(srctree):$(KBUILD_EXTMOD)
+VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 
 export srctree objtree VPATH TOPDIR