diff --git a/Netch/Controllers/DNSController.cs b/Netch/Controllers/DNSController.cs
index add9d5c2..b0564eb6 100644
--- a/Netch/Controllers/DNSController.cs
+++ b/Netch/Controllers/DNSController.cs
@@ -59,6 +59,7 @@ namespace Netch.Controllers
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
             }
             catch (Exception e)
diff --git a/Netch/Controllers/NTTController.cs b/Netch/Controllers/NTTController.cs
index 82843cab..e0003d76 100644
--- a/Netch/Controllers/NTTController.cs
+++ b/Netch/Controllers/NTTController.cs
@@ -73,6 +73,7 @@ namespace Netch.Controllers
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
             }
             catch (Exception e)
diff --git a/Netch/Controllers/PrivoxyController.cs b/Netch/Controllers/PrivoxyController.cs
index 9eedf5ac..e71ec014 100644
--- a/Netch/Controllers/PrivoxyController.cs
+++ b/Netch/Controllers/PrivoxyController.cs
@@ -73,6 +73,7 @@ namespace Netch.Controllers
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
             }
             catch (Exception)
diff --git a/Netch/Controllers/SSController.cs b/Netch/Controllers/SSController.cs
index 17a9267a..fb903f16 100644
--- a/Netch/Controllers/SSController.cs
+++ b/Netch/Controllers/SSController.cs
@@ -117,12 +117,17 @@ namespace Netch.Controllers
         {
             try
             {
+                if (Global.Settings.BootShadowsocksFromDLL)
+                {
+                    NativeMethods.Shadowsocks.Stop();
+                    return;
+                }
+
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
-                if (Global.Settings.BootShadowsocksFromDLL)
-                    NativeMethods.Shadowsocks.Stop();
             }
             catch (Exception e)
             {
diff --git a/Netch/Controllers/SSRController.cs b/Netch/Controllers/SSRController.cs
index c4daf2a1..f1b74721 100644
--- a/Netch/Controllers/SSRController.cs
+++ b/Netch/Controllers/SSRController.cs
@@ -106,6 +106,7 @@ namespace Netch.Controllers
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
             }
             catch (Exception e)
diff --git a/Netch/Controllers/VMessController.cs b/Netch/Controllers/VMessController.cs
index 2e6e4a7a..4acea7d6 100644
--- a/Netch/Controllers/VMessController.cs
+++ b/Netch/Controllers/VMessController.cs
@@ -216,6 +216,7 @@ namespace Netch.Controllers
                 if (Instance != null && !Instance.HasExited)
                 {
                     Instance.Kill();
+                    Instance.WaitForExit();
                 }
             }
             catch (Exception e)