diff --git a/config.c b/config.c
index 3cfeb3d8bd..f561631374 100644
--- a/config.c
+++ b/config.c
@@ -1566,6 +1566,8 @@ static int git_default_core_config(const char *var, const char *value,
 		else if (!strcasecmp(value, "auto"))
 			auto_comment_line_char = 1;
 		else if (value[0] && !value[1]) {
+			if (value[0] == '\n')
+				return error(_("core.commentChar cannot be newline"));
 			comment_line_char = value[0];
 			auto_comment_line_char = 0;
 		} else
diff --git a/t/t0030-stripspace.sh b/t/t0030-stripspace.sh
index d1b3be8725..e399dd9189 100755
--- a/t/t0030-stripspace.sh
+++ b/t/t0030-stripspace.sh
@@ -401,6 +401,11 @@ test_expect_success 'strip comments with changed comment char' '
 	test -z "$(echo "; comment" | git -c core.commentchar=";" stripspace -s)"
 '
 
+test_expect_success 'newline as commentchar is forbidden' '
+	test_must_fail git -c core.commentChar="$LF" stripspace -s 2>err &&
+	grep "core.commentChar cannot be newline" err
+'
+
 test_expect_success '-c with single line' '
 	printf "# foo\n" >expect &&
 	printf "foo" | git stripspace -c >actual &&