diff --git a/t/t4201-shortlog.sh b/t/t4201-shortlog.sh
index 672b28859f..405b971191 100755
--- a/t/t4201-shortlog.sh
+++ b/t/t4201-shortlog.sh
@@ -50,6 +50,6 @@ test_expect_success 'shortlog wrapping' 'test_cmp expect out'
 git log HEAD > log
 GIT_DIR=non-existing git shortlog -w < log > out
 
-test_expect_success 'shortlog from non-git directory' 'diff -u expect out'
+test_expect_success 'shortlog from non-git directory' 'test_cmp expect out'
 
 test_done
diff --git a/t/t6031-merge-recursive.sh b/t/t6031-merge-recursive.sh
index 5bb6b93780..c8310aee4f 100755
--- a/t/t6031-merge-recursive.sh
+++ b/t/t6031-merge-recursive.sh
@@ -42,7 +42,7 @@ test_expect_success 'mode change in both branches: expect conflict' '
 		echo "100755 $H 2	file2"
 		echo "100644 $H 3	file2"
 	) >expect &&
-	diff -u actual expect &&
+	test_cmp actual expect &&
 	test -x file2
 '