diff --git a/sigar_common_darwin.go b/sigar_common_darwin.go
index db02df71d..89e660a08 100644
--- a/sigar_common_darwin.go
+++ b/sigar_common_darwin.go
@@ -26,6 +26,8 @@ import (
 	"syscall"
 	"time"
 	"unsafe"
+
+	"golang.org/x/sys/unix"
 )
 
 // Get fetches LoadAverage data
@@ -471,21 +473,23 @@ func vmInfo(vmstat *C.vm_statistics_data_t) error {
 
 // generic Sysctl buffer unmarshalling
 func sysctlbyname(name string, data interface{}) (err error) {
-	val, err := syscall.Sysctl(name)
-	if err != nil {
-		return err
-	}
-
-	buf := []byte(val)
-
 	switch v := data.(type) {
 	case *uint64:
-		*v = *(*uint64)(unsafe.Pointer(&buf[0]))
-		return
-	}
+		res, err := unix.SysctlUint64(name)
+		if err != nil {
+			return err
+		}
+		*v = res
+		return nil
+	default:
+		val, err := syscall.Sysctl(name)
+		if err != nil {
+			return err
+		}
 
-	bbuf := bytes.NewBuffer([]byte(val))
-	return binary.Read(bbuf, binary.LittleEndian, data)
+		bbuf := bytes.NewBuffer([]byte(val))
+		return binary.Read(bbuf, binary.LittleEndian, data)
+	}
 }
 
 func taskInfo(pid int, info *C.struct_proc_taskallinfo) error {