diff --git a/Makefile b/Makefile
index d8bbda782..0ec6b42bd 100644
--- a/Makefile
+++ b/Makefile
@@ -428,5 +428,5 @@ verify-modules: modules
 .PHONY: verify-gen
 verify-gen: generate
 	@if !(git diff --quiet HEAD); then \
-		echo "generated files are out of date, run make generate"; exit 1; \
+		echo "generated files are out of date, run make generate"; git diff HEAD; exit 1; \
 	fi