diff --git a/hdf_service/distributed_audio/mfc_test/distributedaudiotest.cpp b/hdf_service/distributed_audio/mfc_test/distributedaudiotest.cpp
index de2c73065f999024665ba945a8310ecc0a7b93d0..7f7c44319a4eb1b8d457f9b0b9d86fab89ddb09a 100644
--- a/hdf_service/distributed_audio/mfc_test/distributedaudiotest.cpp
+++ b/hdf_service/distributed_audio/mfc_test/distributedaudiotest.cpp
@@ -72,7 +72,7 @@ FILE *g_micFile = nullptr;
 static std::string CloseSpk();
 static std::string CloseMic();
 
-int64_t GetNowTimeUs()
+static int64_t GetNowTimeUs()
 {
     std::chrono::microseconds nowUs =
         std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::system_clock::now().time_since_epoch());