diff --git a/owrx/property/validators.py b/owrx/property/validators.py
index 5d474bc..9a9ebfe 100644
--- a/owrx/property/validators.py
+++ b/owrx/property/validators.py
@@ -84,7 +84,7 @@ class RegexValidator(Validator):
         self.regex = regex
 
     def isValid(self, value):
-        return self.regex.match(value) is not None
+        return isinstance(value, str) and self.regex.match(value) is not None
 
 
 validator_types = {
diff --git a/test/property/validators/test_regex_validator.py b/test/property/validators/test_regex_validator.py
index 1bdfb6c..2151d1b 100644
--- a/test/property/validators/test_regex_validator.py
+++ b/test/property/validators/test_regex_validator.py
@@ -11,3 +11,7 @@ class RegexValidatorTest(TestCase):
     def testDoesntMatchRegex(self):
         validator = RegexValidator(re.compile("abc"))
         self.assertFalse(validator.isValid("xyz"))
+
+    def testFailsIfValueIsNoString(self):
+        validator = RegexValidator(re.compile("abc"))
+        self.assertFalse(validator.isValid(42))