diff --git a/t/t1006-cat-file.sh b/t/t1006-cat-file.sh
index f123ef1e36..1f61b666a7 100755
--- a/t/t1006-cat-file.sh
+++ b/t/t1006-cat-file.sh
@@ -197,7 +197,7 @@ $content"
     # FIXME: %(rest) is incompatible with object names that include whitespace,
     # e.g. HEAD:path/to/a/file with spaces. Use the resolved OID as input to
     # test this instead of the raw object name.
-    if echo "$object_name" | grep " "; then
+    if echo "$object_name" | grep -q " "; then
 	test_rest=test_expect_failure
     else
 	test_rest=test_expect_success