diff --git a/lib/Makefile b/lib/Makefile
index cf2a6778453d..479ac866cd26 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -223,7 +223,7 @@ KCOV_INSTRUMENT_stackdepot.o := n
 libfdt_files = fdt.o fdt_ro.o fdt_wip.o fdt_rw.o fdt_sw.o fdt_strerror.o \
 	       fdt_empty_tree.o
 $(foreach file, $(libfdt_files), \
-	$(eval CFLAGS_$(file) = -I$(src)/../scripts/dtc/libfdt))
+	$(eval CFLAGS_$(file) = -I $(srctree)/scripts/dtc/libfdt))
 lib-$(CONFIG_LIBFDT) += $(libfdt_files)
 
 obj-$(CONFIG_RBTREE_TEST) += rbtree_test.o