diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 59620b1..b0d067b 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -87,6 +87,11 @@
 # $(Q)$(MAKE) $(build)=dir
 build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj
 
+# Prefix -I with $(srctree) if it is not an absolute path
+addtree = $(if $(filter-out -I/%,$(1)),$(patsubst -I%,-I$(srctree)/%,$(1))) $(1)
+# Find all -I options and call addtree
+flags = $(foreach o,$($(1)),$(if $(filter -I%,$(o)),$(call addtree,$(o)),$(o)))
+
 # If quiet is set, only print short version of command
 cmd = @$(echo-cmd) $(cmd_$(1))