diff --git a/awx/main/models/inventory.py b/awx/main/models/inventory.py
index 5ea55da1b5..e52bbc10a3 100644
--- a/awx/main/models/inventory.py
+++ b/awx/main/models/inventory.py
@@ -1017,7 +1017,7 @@ class InventorySourceOptions(BaseModel):
         if self.source != 'ec2':
             return ''
         invalid_filters = []
-        instance_filter_re = re.compile(r'^(?:tag:.+)|(?:[a-z][a-z\.-]*[a-z])=.*$')
+        instance_filter_re = re.compile(r'^((tag:.+)|([a-z][a-z\.-]*[a-z]))=.*$')
         for instance_filter in instance_filters.split(','):
             instance_filter = instance_filter.strip()
             if not instance_filter:
@@ -1026,6 +1026,8 @@ class InventorySourceOptions(BaseModel):
                 invalid_filters.append(instance_filter)
                 continue
             instance_filter_name = instance_filter.split('=', 1)[0]
+            if instance_filter_name.startswith('tag:'):
+                continue
             if instance_filter_name not in self.INSTANCE_FILTER_NAMES:
                 invalid_filters.append(instance_filter)
         if invalid_filters:
diff --git a/awx/main/tests/inventory.py b/awx/main/tests/inventory.py
index db6b7714ee..2583c95334 100644
--- a/awx/main/tests/inventory.py
+++ b/awx/main/tests/inventory.py
@@ -1306,10 +1306,26 @@ class InventoryUpdatesTest(BaseTransactionTest):
             response = self.put(inv_src_url1, inv_src_data, expect=400)
         # Invalid field name for instance filters.
         inv_src_data['instance_filters'] = 'foo=bar,'
+        with self.current_user(self.super_django_user):
+            response = self.put(inv_src_url1, inv_src_data, expect=400)
+        # Invalid tag expression for instance filters.
+        inv_src_data['instance_filters'] = 'tag:=,'
+        with self.current_user(self.super_django_user):
+            response = self.put(inv_src_url1, inv_src_data, expect=400)
+        # Another invalid tag expression for instance filters.
+        inv_src_data['instance_filters'] = 'tag:Name,'
         with self.current_user(self.super_django_user):
             response = self.put(inv_src_url1, inv_src_data, expect=400)
         # Valid string for instance filters.
         inv_src_data['instance_filters'] = 'tag-key=Name'
+        with self.current_user(self.super_django_user):
+            response = self.put(inv_src_url1, inv_src_data, expect=200)
+        # Another valid value for instance filters.
+        inv_src_data['instance_filters'] = 'tag:Name=test*'
+        with self.current_user(self.super_django_user):
+            response = self.put(inv_src_url1, inv_src_data, expect=200)
+        # Another valid instance filter with nothing after =.
+        inv_src_data['instance_filters'] = 'tag:Name='
         with self.current_user(self.super_django_user):
             response = self.put(inv_src_url1, inv_src_data, expect=200)
         # Invalid string for group_by.