diff --git a/src/crow_test.cpp b/src/crow_test.cpp
index e84c1a5..942095d 100644
--- a/src/crow_test.cpp
+++ b/src/crow_test.cpp
@@ -556,7 +556,7 @@
 
   auto ret = json::load(
       R"---({"balloons":[{"mode":"ellipse","left":0.036303908355795146,"right":0.18320417789757412,"top":0.05319940476190476,"bottom":0.15224702380952382,"index":"0"},{"mode":"ellipse","left":0.3296201145552561,"right":0.47921580188679247,"top":0.05873511904761905,"bottom":0.1577827380952381,"index":"1"},{"mode":"ellipse","left":0.4996841307277628,"right":0.6425412735849056,"top":0.052113095238095236,"bottom":0.12830357142857143,"index":"2"},{"mode":"ellipse","left":0.7871041105121294,"right":0.954220013477089,"top":0.05869047619047619,"bottom":0.1625,"index":"3"},{"mode":"ellipse","left":0.8144794474393531,"right":0.9721613881401617,"top":0.1399404761904762,"bottom":0.24470238095238095,"index":"4"},{"mode":"ellipse","left":0.04527459568733154,"right":0.2096950808625337,"top":0.35267857142857145,"bottom":0.42791666666666667,"index":"5"},{"mode":"ellipse","left":0.855731974393531,"right":0.9352467991913747,"top":0.3816220238095238,"bottom":0.4282886904761905,"index":"6"},{"mode":"ellipse","left":0.39414167789757415,"right":0.5316079851752021,"top":0.3809375,"bottom":0.4571279761904762,"index":"7"},{"mode":"ellipse","left":0.03522995283018868,"right":0.1915641846361186,"top":0.6164136904761904,"bottom":0.7192708333333333,"index":"8"},{"mode":"ellipse","left":0.05675117924528302,"right":0.21308541105121293,"top":0.7045386904761904,"bottom":0.8016815476190476,"index":"9"}]})---");
-  ASSERT_TRUE(ret);
+  ASSERT_TRUE(static_cast<bool>(ret));
 }
 
 TEST(Crow, json_read_unescaping) {