diff --git a/Makefile b/Makefile
index 567b859a47..0025b98b95 100644
--- a/Makefile
+++ b/Makefile
@@ -1063,6 +1063,7 @@ endif
 -include config.mak
 
 ifdef CHECK_HEADER_DEPENDENCIES
+COMPUTE_HEADER_DEPENDENCIES =
 USE_COMPUTED_HEADER_DEPENDENCIES =
 endif