diff --git a/builtin-commit.c b/builtin-commit.c
index 93ca496357..591d16b91e 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -1015,9 +1015,11 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	}
 
 	/* Truncate the message just before the diff, if any. */
-	p = strstr(sb.buf, "\ndiff --git a/");
-	if (p != NULL)
-		strbuf_setlen(&sb, p - sb.buf + 1);
+	if (verbose) {
+		p = strstr(sb.buf, "\ndiff --git ");
+		if (p != NULL)
+			strbuf_setlen(&sb, p - sb.buf + 1);
+	}
 
 	if (cleanup_mode != CLEANUP_NONE)
 		stripspace(&sb, cleanup_mode == CLEANUP_ALL);
diff --git a/t/t7507-commit-verbose.sh b/t/t7507-commit-verbose.sh
new file mode 100755
index 0000000000..519adba80b
--- /dev/null
+++ b/t/t7507-commit-verbose.sh
@@ -0,0 +1,73 @@
+#!/bin/sh
+
+test_description='verbose commit template'
+. ./test-lib.sh
+
+cat >check-for-diff <<EOF
+#!$SHELL_PATH
+exec grep '^diff --git' "\$1"
+EOF
+chmod +x check-for-diff
+test_set_editor "$PWD/check-for-diff"
+
+cat >message <<'EOF'
+subject
+
+body
+EOF
+
+test_expect_success 'setup' '
+	echo content >file &&
+	git add file &&
+	git commit -F message
+'
+
+test_expect_failure 'initial commit shows verbose diff' '
+	git commit --amend -v
+'
+
+test_expect_success 'second commit' '
+	echo content modified >file &&
+	git add file &&
+	git commit -F message
+'
+
+check_message() {
+	git log -1 --pretty=format:%s%n%n%b >actual &&
+	test_cmp "$1" actual
+}
+
+test_expect_success 'verbose diff is stripped out' '
+	git commit --amend -v &&
+	check_message message
+'
+
+test_expect_success 'verbose diff is stripped out (mnemonicprefix)' '
+	git config diff.mnemonicprefix true &&
+	git commit --amend -v &&
+	check_message message
+'
+
+cat >diff <<'EOF'
+This is an example commit message that contains a diff.
+
+diff --git c/file i/file
+new file mode 100644
+index 0000000..f95c11d
+--- /dev/null
++++ i/file
+@@ -0,0 +1 @@
++this is some content
+EOF
+
+test_expect_success 'diff in message is retained without -v' '
+	git commit --amend -F diff &&
+	check_message diff
+'
+
+test_expect_failure 'diff in message is retained with -v' '
+	git commit --amend -F diff -v &&
+	check_message diff
+'
+
+test_done