diff --git a/lib/cpp/test/OpenSSLManualInitTest.cpp b/lib/cpp/test/OpenSSLManualInitTest.cpp
index a751806..935a205 100644
--- a/lib/cpp/test/OpenSSLManualInitTest.cpp
+++ b/lib/cpp/test/OpenSSLManualInitTest.cpp
@@ -88,6 +88,6 @@
 
   suite->add(BOOST_TEST_CASE(test_openssl_availability));
 
-  return NULL;
+  return nullptr;
 }
 #endif
\ No newline at end of file