diff --git a/libuavcan/include/uavcan/node/service_client.hpp b/libuavcan/include/uavcan/node/service_client.hpp
index 2aefd9c1f3..8a9dced967 100644
--- a/libuavcan/include/uavcan/node/service_client.hpp
+++ b/libuavcan/include/uavcan/node/service_client.hpp
@@ -407,7 +407,7 @@ int ServiceClient<DataType_, Callback_, NumStaticCalls_>::addCallState(ServiceCa
     return 0;
 #else
     (void)call_id;
-    return 0;
+    return -ErrNotInited;
 #endif
 }