diff --git a/authentik/lib/expression/evaluator.py b/authentik/lib/expression/evaluator.py
index 7681ef6c0..452eb4a85 100644
--- a/authentik/lib/expression/evaluator.py
+++ b/authentik/lib/expression/evaluator.py
@@ -3,6 +3,7 @@ import re
 from textwrap import indent
 from typing import Any, Iterable, Optional
 
+from django.core.exceptions import FieldError
 from requests import Session
 from rest_framework.serializers import ValidationError
 from sentry_sdk.hub import Hub
@@ -29,10 +30,10 @@ class BaseEvaluator:
         # update website/docs/expressions/_objects.md
         # update website/docs/expressions/_functions.md
         self._globals = {
-            "regex_match": BaseEvaluator.expr_filter_regex_match,
-            "regex_replace": BaseEvaluator.expr_filter_regex_replace,
-            "ak_is_group_member": BaseEvaluator.expr_func_is_group_member,
-            "ak_user_by": BaseEvaluator.expr_func_user_by,
+            "regex_match": BaseEvaluator.expr_regex_match,
+            "regex_replace": BaseEvaluator.expr_regex_replace,
+            "ak_is_group_member": BaseEvaluator.expr_is_group_member,
+            "ak_user_by": BaseEvaluator.expr_user_by,
             "ak_logger": get_logger(),
             "requests": Session(),
         }
@@ -40,25 +41,28 @@ class BaseEvaluator:
         self._filename = "BaseEvalautor"
 
     @staticmethod
-    def expr_filter_regex_match(value: Any, regex: str) -> bool:
+    def expr_regex_match(value: Any, regex: str) -> bool:
         """Expression Filter to run re.search"""
-        return re.search(regex, value) is None
+        return re.search(regex, value) is not None
 
     @staticmethod
-    def expr_filter_regex_replace(value: Any, regex: str, repl: str) -> str:
+    def expr_regex_replace(value: Any, regex: str, repl: str) -> str:
         """Expression Filter to run re.sub"""
         return re.sub(regex, repl, value)
 
     @staticmethod
-    def expr_func_user_by(**filters) -> Optional[User]:
+    def expr_user_by(**filters) -> Optional[User]:
         """Get user by filters"""
-        users = User.objects.filter(**filters)
-        if users:
-            return users.first()
-        return None
+        try:
+            users = User.objects.filter(**filters)
+            if users:
+                return users.first()
+            return None
+        except FieldError:
+            return None
 
     @staticmethod
-    def expr_func_is_group_member(user: User, **group_filters) -> bool:
+    def expr_is_group_member(user: User, **group_filters) -> bool:
         """Check if `user` is member of group with name `group_name`"""
         return user.ak_groups.filter(**group_filters).exists()
 
diff --git a/authentik/lib/tests/test_evaluator.py b/authentik/lib/tests/test_evaluator.py
new file mode 100644
index 000000000..931224d46
--- /dev/null
+++ b/authentik/lib/tests/test_evaluator.py
@@ -0,0 +1,32 @@
+"""Test Evaluator base functions"""
+from django.test import TestCase
+
+from authentik.core.models import User
+from authentik.lib.expression.evaluator import BaseEvaluator
+
+
+class TestEvaluator(TestCase):
+    """Test Evaluator base functions"""
+
+    def test_regex_match(self):
+        """Test expr_regex_match"""
+        self.assertFalse(BaseEvaluator.expr_regex_match("foo", "bar"))
+        self.assertTrue(BaseEvaluator.expr_regex_match("foo", "foo"))
+
+    def test_regex_replace(self):
+        """Test expr_regex_replace"""
+        self.assertEqual(BaseEvaluator.expr_regex_replace("foo", "o", "a"), "faa")
+
+    def test_user_by(self):
+        """Test expr_user_by"""
+        self.assertIsNotNone(BaseEvaluator.expr_user_by(username="akadmin"))
+        self.assertIsNone(BaseEvaluator.expr_user_by(username="bar"))
+        self.assertIsNone(BaseEvaluator.expr_user_by(foo="bar"))
+
+    def test_is_group_member(self):
+        """Test expr_is_group_member"""
+        self.assertFalse(
+            BaseEvaluator.expr_is_group_member(
+                User.objects.get(username="akadmin"), name="test"
+            )
+        )
diff --git a/schema.yml b/schema.yml
index b0dbb39cb..8e85f84f7 100644
--- a/schema.yml
+++ b/schema.yml
@@ -1,7 +1,7 @@
 openapi: 3.0.3
 info:
   title: authentik
-  version: 2021.6.1
+  version: 2021.6.2
   description: Making authentication simple.
   contact:
     email: hello@beryju.org