diff --git a/extras/tests/MsgPackSerializer/serializeObject.cpp b/extras/tests/MsgPackSerializer/serializeObject.cpp
index 215b51c6..3037b219 100644
--- a/extras/tests/MsgPackSerializer/serializeObject.cpp
+++ b/extras/tests/MsgPackSerializer/serializeObject.cpp
@@ -44,7 +44,7 @@ TEST_CASE("serialize MsgPack object") {
   SECTION("map 16") {
     for (int i = 0; i < 16; ++i) {
       char key[16];
-      sprintf(key, "i%X", i);
+      snprintf(key, 16, "i%X", i);
       object[key] = i;
     }