diff --git a/test/libsolidity/util/TestFileParser.cpp b/test/libsolidity/util/TestFileParser.cpp
index 8782fe01d..397550e5d 100644
--- a/test/libsolidity/util/TestFileParser.cpp
+++ b/test/libsolidity/util/TestFileParser.cpp
@@ -550,6 +550,11 @@ void TestFileParser::Scanner::scanNextToken()
 				token = selectToken(Token::Whitespace);
 			else if (isEndOfLine())
 				token = selectToken(Token::EOS);
+			else
+				throw Error(
+					Error::Type::ParserError,
+					"Unexpected character: '" + string{current()} + "'"
+				);
 			break;
 		}
 	}
diff --git a/test/libsolidity/util/TestFileParserTests.cpp b/test/libsolidity/util/TestFileParserTests.cpp
index 03325dea2..38e29968c 100644
--- a/test/libsolidity/util/TestFileParserTests.cpp
+++ b/test/libsolidity/util/TestFileParserTests.cpp
@@ -775,6 +775,14 @@ BOOST_AUTO_TEST_CASE(call_arrow_missing)
 	BOOST_REQUIRE_THROW(parse(source), langutil::Error);
 }
 
+BOOST_AUTO_TEST_CASE(call_unexpected_character)
+{
+	char const* source = R"(
+		// f() -> ??
+	)";
+	BOOST_REQUIRE_THROW(parse(source), langutil::Error);
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }