diff --git a/source/client/src/clientEnv.c b/source/client/src/clientEnv.c
index 212c42125e..85624c31c5 100644
--- a/source/client/src/clientEnv.c
+++ b/source/client/src/clientEnv.c
@@ -732,7 +732,7 @@ int taos_options_imp(TSDB_OPTION option, const char *str) {
         return -1;
       }
       newstr[0] = '"';
-      strncpy(newstr+1, str, len);
+      memcpy(newstr+1, str, len);
       newstr[len + 1] = '"';
       newstr[len + 2] = '\0';
       str = newstr;