diff --git a/compat/winansi.c b/compat/winansi.c
index 3abe8dd5a2711b..855897e6dd45f7 100644
--- a/compat/winansi.c
+++ b/compat/winansi.c
@@ -573,6 +573,8 @@ static void detect_msys_tty(int fd)
 	if (!NT_SUCCESS(NtQueryObject(h, ObjectNameInformation,
 			buffer, sizeof(buffer) - 2, &result)))
 		return;
+	if (result <= sizeof(*nameinfo))
+		return;
 	name = nameinfo->Name.Buffer;
 	name[nameinfo->Name.Length / sizeof(*name)] = 0;