TypeDoesNotContainType issues with is_numeric() and strings

[erunion]

I have the following code that's parsing annotations for error codes, by looking for (\SomeError\Class::CASE) or (1337). Psalm seems to be having issues with the is_numeric check I'm doing to verify if the found error code is a numeric, or a FQN class name.

if (preg_match(self::REGEX_ERROR_CODE, $doc, $matches)) {
    $error_code = substr($matches[1], 1, -1);
    if (is_numeric($error_code)) {
        $parsed['error_code'] = $error_code;
    } else {
        if (!defined($error_code)) {
            throw UncallableErrorCodeException::create($this->docblock, $this->controller, $this->method);
        }

        $parsed['error_code'] = constant($error_code);
    }

    $doc = trim(preg_replace(self::REGEX_ERROR_CODE, '', $doc));
}

$ ./vendor/bin/psalm 
ERROR: TypeDoesNotContainType - src/Parser/Annotations/ThrowsAnnotation.php:116 - Cannot resolve types for $error_code - string does not contain numeric
            if (is_numeric($error_code)) {

Ideas?

[muglug]

Definitely a bug, will fix within 24 hours or so.