diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index 903af14294..6ee7700eb4 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -49,7 +49,7 @@ while (<>) {
 	/\bexport\s+[A-Za-z0-9_]*=/ and err '"export FOO=bar" is not portable (use FOO=bar && export FOO)';
 	/\blocal\s+[A-Za-z0-9_]*=\$([A-Za-z0-9_{]|[(][^(])/ and
 		err q(quote "$val" in 'local var=$val');
-	/^\s*([A-Z0-9_]+=(\w*|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and
+	/\b([A-Z0-9_]+=(\w*|(["']).*?\3)\s+)+(\w+)/ and !/test_env.+=/ and exists($func{$4}) and
 		err '"FOO=bar shell_func" is not portable (use test_env FOO=bar shell_func)';
 	$line = '';
 	# this resets our $. for each file