diff --git a/protect.go b/protect.go
index e2e5672..0e90d2d 100644
--- a/protect.go
+++ b/protect.go
@@ -25,7 +25,7 @@ func Unveil(path string, flags string) {}
 // processes filesystem view.
 //
 // On non-OpenBSD machines this call is a noop.
-func UnveilBlock() {}
+func UnveilBlock() error {}
 
 // Pledge wraps OpenBSD's pledge(2) system call. One can use this to limit
 // the system calls a process can make.
diff --git a/protect_openbsd.go b/protect_openbsd.go
index aa90bad..254f303 100644
--- a/protect_openbsd.go
+++ b/protect_openbsd.go
@@ -31,8 +31,8 @@ func Unveil(path string, flags string) {
 // processes filesystem view.
 //
 // On non-OpenBSD machines this call is a noop.
-func UnveilBlock() {
-	unix.UnveilBlock()
+func UnveilBlock() error {
+	return unix.UnveilBlock()
 }
 
 // Pledge wraps OpenBSD's pledge(2) system call. One can use this to limit