diff --git a/start.py b/start.py
index 0d4addf59f..05069862bf 100644
--- a/start.py
+++ b/start.py
@@ -124,7 +124,10 @@ else:
 
 import igniter  # noqa: E402
 from igniter import BootstrapRepos  # noqa: E402
-from igniter.tools import get_openpype_path_from_db  # noqa
+from igniter.tools import (
+    get_openpype_path_from_db,
+    validate_mongo_connection
+)  # noqa
 from igniter.bootstrap_repos import OpenPypeVersion  # noqa: E402
 
 bootstrap = BootstrapRepos()
@@ -306,20 +309,32 @@ def _determine_mongodb() -> str:
     openpype_mongo = os.getenv("OPENPYPE_MONGO", None)
     if not openpype_mongo:
         # try system keyring
+        try:
+            openpype_mongo = bootstrap.secure_registry.get_item(
+                "openPypeMongo"
+            )
+        except ValueError:
+            pass
+
+    if openpype_mongo:
+        result, msg = validate_mongo_connection(openpype_mongo)
+        if not result:
+            print(msg)
+            openpype_mongo = None
+
+    if not openpype_mongo:
+        print("*** No DB connection string specified.")
+        print("--- launching setup UI ...")
+
+        result = igniter.open_dialog()
+        if result == 0:
+            raise RuntimeError("MongoDB URL was not defined")
+
         try:
             openpype_mongo = bootstrap.secure_registry.get_item(
                 "openPypeMongo")
         except ValueError:
-            print("*** No DB connection string specified.")
-            print("--- launching setup UI ...")
-            import igniter
-            igniter.open_dialog()
-
-            try:
-                openpype_mongo = bootstrap.secure_registry.get_item(
-                    "openPypeMongo")
-            except ValueError:
-                raise RuntimeError("missing mongodb url")
+            raise RuntimeError("Missing MongoDB url")
 
     return openpype_mongo