diff --git a/mergin/client.py b/mergin/client.py
index ec6d155..101c62e 100644
--- a/mergin/client.py
+++ b/mergin/client.py
@@ -380,14 +380,18 @@ def server_type(self):
             try:
                 resp = self.get("/config", validate_auth=False)
                 config = json.load(resp)
-                if config["server_type"] == "ce":
+                stype = config.get("server_type")
+                if stype == "ce":
                     self._server_type = ServerType.CE
-                elif config["server_type"] == "ee":
+                elif stype == "ee":
                     self._server_type = ServerType.EE
-                elif config["server_type"] == "saas":
+                elif stype == "saas":
                     self._server_type = ServerType.SAAS
-            except (ClientError, KeyError):
-                self._server_type = ServerType.OLD
+            except ClientError as e:
+                if getattr(e, "http_error", None) == 404:
+                    self._server_type = ServerType.OLD
+                else:
+                    raise
 
         return self._server_type
 
diff --git a/mergin/test/test_client.py b/mergin/test/test_client.py
index 58278b5..07cdeec 100644
--- a/mergin/test/test_client.py
+++ b/mergin/test/test_client.py
@@ -11,6 +11,8 @@
 import sqlite3
 import glob
 
+from unittest.mock import patch, Mock
+
 from .. import InvalidProject
 from ..client import (
     MerginClient,
@@ -3008,3 +3010,19 @@ def test_validate_auth(mc: MerginClient):
     # this should pass and not raise an error, as the client is able to re-login
     with pytest.raises(LoginError):
         mc_auth_token_login_wrong_password.validate_auth()
+
+
+def test_server_type(mc):
+    """Test mc.server_type() method"""
+    # success
+    assert mc.server_type() == ServerType.SAAS
+    mc._server_type = None
+    with patch("mergin.client.MerginClient.get") as mock_client_get:
+        # 404
+        mock_client_get.side_effect = ClientError(detail="Not found", http_error=404)
+        assert mc.server_type() == ServerType.OLD
+        mc._server_type = None
+        # 503
+        mock_client_get.side_effect = ClientError(detail="Service unavailable", http_error=503)
+        with pytest.raises(ClientError, match="Service unavailable"):
+            mc.server_type()