diff --git a/test/parallel_api/ranges/std_ranges_test.h b/test/parallel_api/ranges/std_ranges_test.h
index 28ed1856d3e..9e2522eb468 100644
--- a/test/parallel_api/ranges/std_ranges_test.h
+++ b/test/parallel_api/ranges/std_ranges_test.h
@@ -68,7 +68,7 @@ auto pred3 = [](auto&& val) -> decltype(auto) { return val < 0; };
 struct P2
 {
     P2() {}
-    P2(int v): x(v) {}
+    explicit P2(int v): x(v) {}
     int x = {};
     int y = {};