diff --git a/app/src/main/java/io/nekohasekai/sagernet/bg/GuardedProcessPool.kt b/app/src/main/java/io/nekohasekai/sagernet/bg/GuardedProcessPool.kt
index db70000..cded1ca 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/bg/GuardedProcessPool.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/bg/GuardedProcessPool.kt
@@ -64,6 +64,7 @@ class GuardedProcessPool(private val onFatal: suspend (IOException) -> Unit) : C
                         SystemClock.elapsedRealtime() - startTime < 1000 -> throw IOException(
                             "$cmdName exits too fast (exit code: $exitCode)"
                         )
+
                         exitCode == 128 + OsConstants.SIGKILL -> Logs.w("$cmdName was killed")
                         else -> Logs.w(IOException("$cmdName unexpectedly exits with code $exitCode"))
                     }
@@ -99,6 +100,7 @@ class GuardedProcessPool(private val onFatal: suspend (IOException) -> Unit) : C
     }
 
     override val coroutineContext = Dispatchers.Main.immediate + Job()
+    var processCount = 0
 
     @MainThread
     fun start(
@@ -111,6 +113,7 @@ class GuardedProcessPool(private val onFatal: suspend (IOException) -> Unit) : C
             start() // if start fails, IOException will be thrown directly
             launch { looper(onRestartCallback) }
         }
+        processCount += 1
     }
 
     @MainThread
diff --git a/app/src/main/java/io/nekohasekai/sagernet/bg/proto/TestInstance.kt b/app/src/main/java/io/nekohasekai/sagernet/bg/proto/TestInstance.kt
index e4b85df..73166bb 100644
--- a/app/src/main/java/io/nekohasekai/sagernet/bg/proto/TestInstance.kt
+++ b/app/src/main/java/io/nekohasekai/sagernet/bg/proto/TestInstance.kt
@@ -8,6 +8,7 @@ import io.nekohasekai.sagernet.ktx.Logs
 import io.nekohasekai.sagernet.ktx.runOnDefaultDispatcher
 import io.nekohasekai.sagernet.ktx.tryResume
 import io.nekohasekai.sagernet.ktx.tryResumeWithException
+import kotlinx.coroutines.delay
 import libcore.Libcore
 import kotlin.coroutines.suspendCoroutine
 
@@ -25,6 +26,10 @@ class TestInstance(profile: ProxyEntity, val link: String, val timeout: Int) :
                     try {
                         init()
                         launch()
+                        if (processes.processCount > 0) {
+                            // wait for plugin start
+                            delay(500)
+                        }
                         c.tryResume(Libcore.urlTest(box, link, timeout))
                     } catch (e: Exception) {
                         c.tryResumeWithException(e)