diff --git a/Makefile b/Makefile
index b88b91458f..3df0ab5c76 100644
--- a/Makefile
+++ b/Makefile
@@ -2477,7 +2477,6 @@ dep_args = -MF $(dep_file) -MQ $@ -MMD -MP
 endif
 
 ifneq ($(COMPUTE_HEADER_DEPENDENCIES),yes)
-dep_dirs =
 missing_dep_dirs =
 dep_args =
 endif