diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index a12d865e0..7e26f79c2 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -3282,7 +3282,7 @@ template <> otError Interpreter::Process<Cmd("log")>(Arg aArgs[])
 #if (OPENTHREAD_CONFIG_LOG_OUTPUT == OPENTHREAD_CONFIG_LOG_OUTPUT_DEBUG_UART) && OPENTHREAD_POSIX
     else if (aArgs[0] == "filename")
     {
-        VerifyOrExit(aArgs[1].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(!aArgs[1].IsEmpty(), error = OT_ERROR_INVALID_ARGS);
         SuccessOrExit(error = otPlatDebugUart_logfile(aArgs[1].GetCString()));
     }
 #endif