diff --git a/mobly/controllers/android_device_lib/jsonrpc_client_base.py b/mobly/controllers/android_device_lib/jsonrpc_client_base.py
index 1d6f7aa..2efef97 100644
--- a/mobly/controllers/android_device_lib/jsonrpc_client_base.py
+++ b/mobly/controllers/android_device_lib/jsonrpc_client_base.py
@@ -90,7 +90,7 @@
     """Raised when there is some error in exchanging data with server."""
     NO_RESPONSE_FROM_HANDSHAKE = 'No response from handshake.'
     NO_RESPONSE_FROM_SERVER = 'No response from server.'
-    MISMATCHED_API_ID = 'Mismatched API id.'
+    MISMATCHED_API_ID = 'RPC request-response ID mismatch.'
 
 
 class JsonRpcCommand(object):