diff --git a/t/t0021-conversion.sh b/t/t0021-conversion.sh
index 161f560446..8b66e649e4 100755
--- a/t/t0021-conversion.sh
+++ b/t/t0021-conversion.sh
@@ -276,7 +276,7 @@ test_expect_success 'filter that does not read is fine' '
 	test_cmp expect actual
 '
 
-test_expect_success EXPENSIVE 'filter large file' '
+test_expect_success EXPENSIVE,!MINGW 'filter large file' '
 	test_config filter.largefile.smudge cat &&
 	test_config filter.largefile.clean cat &&
 	for i in $(test_seq 1 2048); do printf "%1048576d" 1; done >2GB &&