diff --git a/source/backend/engine/CarlaEngine.cpp b/source/backend/engine/CarlaEngine.cpp
index f05069d10..c114cf187 100644
--- a/source/backend/engine/CarlaEngine.cpp
+++ b/source/backend/engine/CarlaEngine.cpp
@@ -698,8 +698,7 @@ bool CarlaEngine::removePlugin(const uint id)
     if (pData->options.processMode == ENGINE_PROCESS_MODE_PATCHBAY)
         pData->graph.removePlugin(plugin);
 
-    const bool lockWait(isRunning() /*&& pData->options.processMode != ENGINE_PROCESS_MODE_MULTIPLE_CLIENTS*/);
-    const ScopedActionLock sal(this, kEnginePostActionRemovePlugin, id, 0, lockWait);
+    const ScopedActionLock sal(this, kEnginePostActionRemovePlugin, id, 0);
 
     /*
     for (uint i=id; i < pData->curPluginCount; ++i)
@@ -755,8 +754,7 @@ bool CarlaEngine::removeAllPlugins()
 # endif
 #endif
 
-    const bool lockWait(isRunning());
-    const ScopedActionLock sal(this, kEnginePostActionZeroCount, 0, 0, lockWait);
+    const ScopedActionLock sal(this, kEnginePostActionZeroCount, 0, 0);
 
     callback(ENGINE_CALLBACK_IDLE, 0, 0, 0, 0.0f, nullptr);
 
@@ -892,8 +890,7 @@ bool CarlaEngine::switchPlugins(const uint idA, const uint idB) noexcept
     if (pData->options.processMode == ENGINE_PROCESS_MODE_PATCHBAY)
         pData->graph.replacePlugin(pluginA, pluginB);
 
-    const bool lockWait(isRunning() /*&& pData->options.processMode != ENGINE_PROCESS_MODE_MULTIPLE_CLIENTS*/);
-    const ScopedActionLock sal(this, kEnginePostActionSwitchPlugins, idA, idB, lockWait);
+    const ScopedActionLock sal(this, kEnginePostActionSwitchPlugins, idA, idB);
 
     // TODO
     /*
diff --git a/source/backend/engine/CarlaEngineBridge.cpp b/source/backend/engine/CarlaEngineBridge.cpp
index 2975d17c0..035acdf76 100644
--- a/source/backend/engine/CarlaEngineBridge.cpp
+++ b/source/backend/engine/CarlaEngineBridge.cpp
@@ -93,6 +93,7 @@ public:
           fBaseNameRtClientControl(rtClientBaseName),
           fBaseNameNonRtClientControl(nonRtClientBaseName),
           fBaseNameNonRtServerControl(nonRtServerBaseName),
+          fClosingDown(false),
           fIsOffline(false),
           fFirstIdle(true),
           fLastPingTime(-1)
@@ -234,6 +235,9 @@ public:
 
     bool isRunning() const noexcept override
     {
+        if (fClosingDown)
+            return false;
+
         return isThreadRunning() || ! fFirstIdle;
     }
 
@@ -981,6 +985,7 @@ public:
             }
 
             case kPluginBridgeNonRtClientQuit:
+                fClosingDown = true;
                 signalThreadShouldExit();
                 callback(ENGINE_CALLBACK_QUIT, 0, 0, 0, 0.0f, nullptr);
                 break;
@@ -1320,6 +1325,7 @@ protected:
 
                 case kPluginBridgeRtClientQuit: {
                     quitReceived = true;
+                    fClosingDown = true;
                     signalThreadShouldExit();
                 }   break;
                 }
@@ -1376,6 +1382,7 @@ private:
     CarlaString fBaseNameNonRtClientControl;
     CarlaString fBaseNameNonRtServerControl;
 
+    bool fClosingDown;
     bool fIsOffline;
     bool fFirstIdle;
     int64_t fLastPingTime;
diff --git a/source/backend/engine/CarlaEngineInternal.cpp b/source/backend/engine/CarlaEngineInternal.cpp
index 29ff73149..3e71e3f72 100644
--- a/source/backend/engine/CarlaEngineInternal.cpp
+++ b/source/backend/engine/CarlaEngineInternal.cpp
@@ -712,8 +712,7 @@ PendingRtEventsRunner::~PendingRtEventsRunner() noexcept
 ScopedActionLock::ScopedActionLock(CarlaEngine* const engine,
                                    const EnginePostAction action,
                                    const uint pluginId,
-                                   const uint value,
-                                   const bool lockWait) noexcept
+                                   const uint value) noexcept
     : pData(engine->pData)
 {
     CARLA_SAFE_ASSERT_RETURN(action != kEnginePostActionNull,);
@@ -726,24 +725,41 @@ ScopedActionLock::ScopedActionLock(CarlaEngine* const engine,
         pData->nextAction.opcode    = action;
         pData->nextAction.pluginId  = pluginId;
         pData->nextAction.value     = value;
-        pData->nextAction.needsPost = lockWait;
+        pData->nextAction.needsPost = engine->isRunning();
         pData->nextAction.postDone  = false;
     }
 
-    if (lockWait)
+   #ifdef BUILD_BRIDGE
+    #define ACTION_MSG_PREFIX "Bridge: "
+   #else
+    #define ACTION_MSG_PREFIX ""
+   #endif
+
+    if (pData->nextAction.needsPost)
     {
         // block wait for unlock on processing side
-        carla_stdout("ScopedPluginAction(%i) - blocking START", pluginId);
+        carla_stdout(ACTION_MSG_PREFIX "ScopedPluginAction(%i) - blocking START", pluginId);
+
+        bool engineStoppedWhileWaiting = false;
 
         if (! pData->nextAction.postDone)
         {
-            if (pData->nextAction.sem != nullptr)
-                carla_sem_timedwait(*pData->nextAction.sem, 2000);
-            else
-                carla_sleep(2);
+            for (int i = 10; --i >= 0;)
+            {
+                if (pData->nextAction.sem != nullptr)
+                    carla_sem_timedwait(*pData->nextAction.sem, 200);
+                else
+                    carla_msleep(200);
+
+                if (! engine->isRunning())
+                {
+                    engineStoppedWhileWaiting = true;
+                    break;
+                }
+            }
         }
 
-        carla_stdout("ScopedPluginAction(%i) - blocking DONE", pluginId);
+        carla_stdout(ACTION_MSG_PREFIX "ScopedPluginAction(%i) - blocking DONE", pluginId);
 
         // check if anything went wrong...
         if (! pData->nextAction.postDone)
@@ -763,7 +779,9 @@ ScopedActionLock::ScopedActionLock(CarlaEngine* const engine,
             if (needsCorrection)
             {
                 pData->doNextPluginAction();
-                carla_stderr2("Failed to wait for engine, is audio not running?");
+
+                if (! engineStoppedWhileWaiting)
+                    carla_stderr2(ACTION_MSG_PREFIX "Failed to wait for engine, is audio not running?");
             }
         }
     }
diff --git a/source/backend/engine/CarlaEngineInternal.hpp b/source/backend/engine/CarlaEngineInternal.hpp
index 32c6d1a1a..2fa9a6da9 100644
--- a/source/backend/engine/CarlaEngineInternal.hpp
+++ b/source/backend/engine/CarlaEngineInternal.hpp
@@ -303,7 +303,7 @@ private:
 class ScopedActionLock
 {
 public:
-    ScopedActionLock(CarlaEngine* const engine, const EnginePostAction action, const uint pluginId, const uint value, const bool lockWait) noexcept;
+    ScopedActionLock(CarlaEngine* const engine, const EnginePostAction action, const uint pluginId, const uint value) noexcept;
     ~ScopedActionLock() noexcept;
 
 private:
diff --git a/source/modules/water/threads/ChildProcess.cpp b/source/modules/water/threads/ChildProcess.cpp
index 87f961165..f98875be9 100644
--- a/source/modules/water/threads/ChildProcess.cpp
+++ b/source/modules/water/threads/ChildProcess.cpp
@@ -3,7 +3,7 @@
 
    This file is part of the Water library.
    Copyright (c) 2016 ROLI Ltd.
-   Copyright (C) 2017 Filipe Coelho <falktx@falktx.com>
+   Copyright (C) 2017-2018 Filipe Coelho <falktx@falktx.com>
 
    Permission is granted to use this software under the terms of the ISC license
    http://www.isc.org/downloads/software-support-policy/isc-license/