diff --git a/test/unit.cpp b/test/unit.cpp
index 236e1f93d..7644c9041 100644
--- a/test/unit.cpp
+++ b/test/unit.cpp
@@ -8456,11 +8456,13 @@ TEST_CASE("regression tests")
         SECTION("NAN value")
         {
             CHECK(json(NAN) == json());
+            CHECK(json(static_cast<long double>(NAN)) == json());
         }
 
         SECTION("infinity")
         {
             CHECK(json(INFINITY) == json());
+            CHECK(json(static_cast<long double>(INFINITY)) == json());
         }
     }
 }