diff --git a/builtin/stash.c b/builtin/stash.c
index ca0b4cd33e..8b82053f72 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -761,6 +761,10 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 		free_stash_info(&info);
 		usage_with_options(git_stash_show_usage, options);
 	}
+	if (!rev.diffopt.output_format) {
+		rev.diffopt.output_format = DIFF_FORMAT_PATCH;
+		diff_setup_done(&rev.diffopt);
+	}
 
 	rev.diffopt.flags.recursive = 1;
 	setup_diff_pager(&rev.diffopt);
diff --git a/t/t3903-stash.sh b/t/t3903-stash.sh
index 97cc71fbaf..ea30d5f6a0 100755
--- a/t/t3903-stash.sh
+++ b/t/t3903-stash.sh
@@ -612,6 +612,24 @@ test_expect_success 'stash show -p - no stashes on stack, stash-like argument' '
 	test_cmp expected actual
 '
 
+test_expect_success 'stash show --patience shows diff' '
+	git reset --hard &&
+	echo foo >>file &&
+	STASH_ID=$(git stash create) &&
+	git reset --hard &&
+	cat >expected <<-EOF &&
+	diff --git a/file b/file
+	index 7601807..71b52c4 100644
+	--- a/file
+	+++ b/file
+	@@ -1 +1,2 @@
+	 baz
+	+foo
+	EOF
+	git stash show --patience ${STASH_ID} >actual &&
+	test_cmp expected actual
+'
+
 test_expect_success 'drop: fail early if specified stash is not a stash ref' '
 	git stash clear &&
 	test_when_finished "git reset --hard HEAD && git stash clear" &&