diff --git a/src/pkg/runtime/thread_openbsd.c b/src/pkg/runtime/thread_openbsd.c
index 99c4db972c..2900f370b7 100644
--- a/src/pkg/runtime/thread_openbsd.c
+++ b/src/pkg/runtime/thread_openbsd.c
@@ -172,7 +172,7 @@ runtime·minit(void)
 	// Initialize signal handling
 	m->gsignal = runtime·malg(32*1024);
 	runtime·signalstack((byte*)m->gsignal->stackguard - StackGuard, 32*1024);
-	runtime·sigprocmask(SIG_SETMASK, &sigset_none, nil, sizeof sigset_none);
+	runtime·sigprocmask(SIG_SETMASK, sigset_none);
 }
 
 void