diff --git a/mpp/base/mpp_buffer_impl.cpp b/mpp/base/mpp_buffer_impl.cpp
index 814a236b..dd7d41cd 100644
--- a/mpp/base/mpp_buffer_impl.cpp
+++ b/mpp/base/mpp_buffer_impl.cpp
@@ -427,7 +427,7 @@ MPP_RET mpp_buffer_create(const char *tag, const char *caller,
     if (NULL == tag)
         tag = group->tag;
 
-    strncpy(p->tag, tag, sizeof(p->tag));
+    strncpy(p->tag, tag, sizeof(p->tag) - 1);
     p->caller = caller;
     pthread_mutexattr_t attr;
     pthread_mutexattr_init(&attr);
diff --git a/mpp/base/mpp_meta.cpp b/mpp/base/mpp_meta.cpp
index f34787c5..d4d48055 100644
--- a/mpp/base/mpp_meta.cpp
+++ b/mpp/base/mpp_meta.cpp
@@ -189,7 +189,7 @@ MppMetaImpl *MppMetaService::get_meta(const char *tag, const char *caller)
         const char *tag_src = (tag) ? (tag) : (MODULE_TAG);
         RK_U32 i;
 
-        strncpy(impl->tag, tag_src, sizeof(impl->tag));
+        strncpy(impl->tag, tag_src, sizeof(impl->tag) - 1);
         impl->caller = caller;
         impl->meta_id = MPP_FETCH_ADD(&meta_id, 1);
         INIT_LIST_HEAD(&impl->list_meta);