diff --git a/appium/webdriver/webdriver.py b/appium/webdriver/webdriver.py
index 06801313..5ae6b9ab 100644
--- a/appium/webdriver/webdriver.py
+++ b/appium/webdriver/webdriver.py
@@ -303,7 +303,8 @@ def _update_command_executor(self, keep_alive: bool) -> None:
         direct_port = 'directConnectPort'
         direct_path = 'directConnectPath'
 
-        assert self.caps, 'Driver capabilities must be defined'
+        if not self.caps:
+            raise ValueError('Driver capabilities must be defined')
         if not {direct_protocol, direct_host, direct_port, direct_path}.issubset(set(self.caps)):
             message = 'Direct connect capabilities from server were:\n'
             for key in [direct_protocol, direct_host, direct_port, direct_path]: