diff --git a/tests/test_core.py b/tests/test_core.py
index 2391a84..d21a7a2 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -197,62 +197,60 @@ class MockNetboxVM:
         """Mock save method."""
 
 
-class TestNetboxv2TokenHandling(unittest.TestCase):
-    """Test that sync properly handles NetBox v2 token authentication."""
+class TestNetboxTokenHandling(unittest.TestCase):
+    """Test that sync properly handles NetBox token authentication."""
 
-    @patch("netbox_zabbix_sync.modules.core.ZabbixAPI")
-    @patch("netbox_zabbix_sync.modules.core.nbapi")
-    def test_sync_uses_token_for_netbox_v2(self, mock_api, mock_zabbix_api):
-        """Test that sync uses token authentication for NetBox v2."""
-        # Setup NetBox mock
-        mock_netbox = MagicMock()
-        mock_api.return_value = mock_netbox
-        mock_netbox.version = "4.5"
+    def test_v1_token_with_netbox_45(self):
+        """Test that v1 token with NetBox 4.5+ logs warning but returns True."""
+        syncer = Sync()
 
-        # Setup Zabbix mock
-        mock_zabbix = MagicMock()
-        mock_zabbix_api.return_value = mock_zabbix
-        mock_zabbix.check_auth.return_value = True
-
-        # Test v1 token (should log warning)
         with self.assertLogs("NetBox-Zabbix-sync", level="WARNING") as log_context:
-            syncer_with_v1_token = Sync()
-            result_v1_token = syncer_with_v1_token.connect(
-                nb_host="http://netbox.local",
-                nb_token="token123",  # v1 token (doesn't start with "nbt_")
-                zbx_host="http://zabbix.local",
-                zbx_user="user",
-                zbx_pass="pass",
-                zbx_token=None,
-            )
+            result = syncer._validate_netbox_token("token123", "4.5")
 
-        # Verify v1 token connection succeeded and warning was logged
-        self.assertTrue(result_v1_token)
+        self.assertTrue(result)
         self.assertTrue(
             any("v1 token format" in record.message for record in log_context.records)
         )
 
-        # Test v2 token (should not log warning)
-        # Reset the log capture context
-        syncer_with_v2_token = Sync()
-        with self.assertLogs("NetBox-Zabbix-sync", level="DEBUG") as log_context_v2:
-            result_v2_token = syncer_with_v2_token.connect(
-                nb_host="http://netbox.local",
-                nb_token="nbt_token123",  # v2 token (starts with "nbt_")
-                zbx_host="http://zabbix.local",
-                zbx_user="user",
-                zbx_pass="pass",
-                zbx_token=None,
-            )
+    def test_v2_token_with_netbox_35(self):
+        """Test that v2 token with NetBox < 4.5 logs error and returns False."""
+        syncer = Sync()
 
-        # Verify v2 token connection succeeded and NO warning was logged
-        self.assertTrue(result_v2_token)
-        self.assertFalse(
+        with self.assertLogs("NetBox-Zabbix-sync", level="ERROR") as log_context:
+            result = syncer._validate_netbox_token("nbt_token123", "3.5")
+
+        self.assertFalse(result)
+        self.assertTrue(
             any(
-                "v1 token format" in record.message for record in log_context_v2.records
+                "v2 token format with Netbox version lower than 4.5" in record.message
+                for record in log_context.records
             )
         )
 
+    def test_v2_token_with_netbox_45(self):
+        """Test that v2 token with NetBox 4.5+ logs debug and returns True."""
+        syncer = Sync()
+
+        with self.assertLogs("NetBox-Zabbix-sync", level="DEBUG") as log_context:
+            result = syncer._validate_netbox_token("nbt_token123", "4.5")
+
+        self.assertTrue(result)
+        self.assertTrue(
+            any("v2 token format" in record.message for record in log_context.records)
+        )
+
+    def test_v1_token_with_netbox_35(self):
+        """Test that v1 token with NetBox < 4.5 logs debug and returns True."""
+        syncer = Sync()
+
+        with self.assertLogs("NetBox-Zabbix-sync", level="DEBUG") as log_context:
+            result = syncer._validate_netbox_token("token123", "3.5")
+
+        self.assertTrue(result)
+        self.assertTrue(
+            any("v1 token format" in record.message for record in log_context.records)
+        )
+
 
 class TestSyncNetboxConnection(unittest.TestCase):
     """Test NetBox connection handling in sync function."""