diff --git a/t/t4051-diff-function-context.sh b/t/t4051-diff-function-context.sh
index 3e6b485ecb..30fc5bf2b3 100755
--- a/t/t4051-diff-function-context.sh
+++ b/t/t4051-diff-function-context.sh
@@ -85,6 +85,10 @@ test_expect_success 'setup' '
 
 check_diff changed_hello 'changed function'
 
+test_expect_failure ' context includes comment' '
+	grep "^ .*Hello comment" changed_hello.diff
+'
+
 test_expect_success ' context includes begin' '
 	grep "^ .*Begin of hello" changed_hello.diff
 '
diff --git a/t/t4051/hello.c b/t/t4051/hello.c
index 63b1a1e4ef..73e767e178 100644
--- a/t/t4051/hello.c
+++ b/t/t4051/hello.c
@@ -1,4 +1,7 @@
 
+/*
+ * Hello comment.
+ */
 static void hello(void)	// Begin of hello
 {
 	/*