diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index ff5ca9817a85..8ff0669b3d0d 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -30,7 +30,7 @@ quiet_cmd_modules_install = INSTALL $@
 INSTALL_MOD_DIR ?= extra
 ext-mod-dir = $(INSTALL_MOD_DIR)$(subst $(patsubst %/,%,$(KBUILD_EXTMOD)),,$(@D))
 
-modinst_dir = $(if $(KBUILD_EXTMOD),$(ext-mod-dir),kernel/$(@D))
+modinst_dir ?= $(if $(KBUILD_EXTMOD),$(ext-mod-dir),kernel/$(@D))
 
 $(modules):
 	$(call cmd,modules_install,$(MODLIB)/$(modinst_dir))