diff --git a/src/posix/platform/logging.cpp b/src/posix/platform/logging.cpp
index 717156d54..8dd2a5b67 100644
--- a/src/posix/platform/logging.cpp
+++ b/src/posix/platform/logging.cpp
@@ -36,7 +36,7 @@
 #include <openthread/platform/logging.h>
 
 #if OPENTHREAD_CONFIG_LOG_OUTPUT == OPENTHREAD_CONFIG_LOG_OUTPUT_PLATFORM_DEFINED
-void otPlatLog(otLogLevel aLogLevel, otLogRegion aLogRegion, const char *aFormat, ...)
+OT_TOOL_WEAK void otPlatLog(otLogLevel aLogLevel, otLogRegion aLogRegion, const char *aFormat, ...)
 {
     OT_UNUSED_VARIABLE(aLogRegion);