diff --git a/syscall.go b/syscall.go
index a477920..12db645 100644
--- a/syscall.go
+++ b/syscall.go
@@ -44,23 +44,20 @@ func io_uring_register(fd int, opcode uint32, arg unsafe.Pointer, nrArgs uintptr
 func mmap(addr unsafe.Pointer, length uintptr, prot int, flags int, fd int, offset int64) (xaddr unsafe.Pointer, err error) {
 	r0, _, e1 := syscall.Syscall6(syscall.SYS_MMAP, uintptr(addr), length, uintptr(prot), uintptr(flags), uintptr(fd), uintptr(offset))
 	xaddr = unsafe.Pointer(r0)
-	switch e1 {
-	case 0:
-		err = nil
-	default:
+
+	if e1 != 0 {
 		err = e1
 	}
+
 	return
 }
 
 func munmap(addr unsafe.Pointer, length uintptr) (err error) {
 	_, _, e1 := syscall.Syscall(syscall.SYS_MUNMAP, uintptr(addr), length, 0)
-	switch e1 {
-	case 0:
-		return nil
-	default:
-		return e1
+	if e1 != 0 {
+		err = e1
 	}
+	return
 }
 
 //