diff --git a/services/adapters/broker_adapter.py b/services/adapters/broker_adapter.py
index fd8ed47..d70a53c 100644
--- a/services/adapters/broker_adapter.py
+++ b/services/adapters/broker_adapter.py
@@ -308,6 +308,11 @@ class AlpacaBrokerAdapter(BrokerDataAdapter):
         self.api_secret = api_secret
         if base_url:
             self.base_url = base_url.rstrip("/")
+            # Strip trailing /v2 or /v1 — the adapter adds API version prefixes itself
+            for suffix in ("/v2", "/v1"):
+                if self.base_url.endswith(suffix):
+                    self.base_url = self.base_url[: -len(suffix)]
+                    break
         elif mode == TradingMode.LIVE:
             self.base_url = self.LIVE_BASE_URL
         else: