diff --git a/Makefile.am b/Makefile.am
index 178c36521..7e5f977d0 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -480,6 +480,17 @@ print-subdirs:
 maintainer-tag:
 	git tag -a $(VERSION) -m "Version $(VERSION) ($(BRANCH_TYPE))" -f
 
+# Maintainer only: check EXTRA_DIST rule is complete.
+# (Note you must have done 'make dist')
+
+maintainer-check-extra-dist:
+	zcat $(PACKAGE_NAME)-$(VERSION).tar.gz | tar tf - | sort | \
+	  sed 's,^$(PACKAGE_NAME)-$(VERSION)/,,' > tmp/tarfiles
+	git ls-files | sort > tmp/gitfiles
+	diff -ur tmp/tarfiles tmp/gitfiles | grep '^\+' | \
+	  grep -v src/api-support/[0-9]
+	rm tmp/tarfiles tmp/gitfiles
+
 # Provide help on common Makefile targets.
 
 help: