diff --git a/Makefile b/Makefile
index d4c6548..c894fd5 100644
--- a/Makefile
+++ b/Makefile
@@ -150,9 +150,7 @@ run-shiv:
 release: | test-branch release-on-github print-instructions
 
 test-branch: vars
-ifneq ($(branch),main)
-	$(error Current git branch != main. Merge changes into main first)
-endif
+	$(if $(filter-out $(branch),main),$(error Current git branch != main.))
 
 update-init: vars
 	@sed -i .bak -e "s|^\(__version__ *=\).*|\1 '$(version)'|"  $(init_file)