diff --git a/src/appspawn_server.cpp b/src/appspawn_server.cpp
index def2a98f..10bbd2f5 100644
--- a/src/appspawn_server.cpp
+++ b/src/appspawn_server.cpp
@@ -253,7 +253,7 @@ static void ClearEnvironment(void)
     sigemptyset(&mask);
     sigaddset(&mask, SIGCHLD);
     sigaddset(&mask, SIGTERM);
-    sigprocmask(SIG_UNBLOCK, &mask, NULL);
+    sigprocmask(SIG_UNBLOCK, &mask, nullptr);
     return;
 }