diff --git a/t/t5601-clone.sh b/t/t5601-clone.sh
index 3888c9751f..2424fb3d3e 100755
--- a/t/t5601-clone.sh
+++ b/t/t5601-clone.sh
@@ -628,7 +628,7 @@ test_expect_success 'clone on case-insensitive fs' '
 	)
 '
 
-test_expect_success !MINGW,CASE_INSENSITIVE_FS 'colliding file detection' '
+test_expect_success CASE_INSENSITIVE_FS 'colliding file detection' '
 	grep X icasefs/warning &&
 	grep x icasefs/warning &&
 	test_i18ngrep "the following paths have collided" icasefs/warning