diff --git a/components/buildintf/ideexterntoolintf.pas b/components/buildintf/ideexterntoolintf.pas
index 842ff8defb..c43720a0f5 100644
--- a/components/buildintf/ideexterntoolintf.pas
+++ b/components/buildintf/ideexterntoolintf.pas
@@ -513,8 +513,9 @@ type
   public
     constructor Create(AOwner: TComponent); override;
     destructor Destroy; override;
-    procedure EnterCriticalSection; // always use before access, when using Tool and View: always lock Tool before View
-    procedure LeaveCriticalSection;
+    // always use before access, when using Tool and View: always lock Tool before View
+    procedure EnterCriticalSection; virtual;
+    procedure LeaveCriticalSection; virtual;
     property Thread: TThread read FThread write FThread;
     procedure ConsistencyCheck; virtual;
     procedure AutoFree; // (only main thread) free if not in use
@@ -1225,14 +1226,12 @@ end;
 
 procedure TAbstractExternalTool.EnterCriticalSection;
 begin
-  Sleep(1); // Force context switch to prevent occational crash. Issue #36318, #37883 etc.
   FWorkerMessages.EnterCriticalSection;
 end;
 
 procedure TAbstractExternalTool.LeaveCriticalSection;
 begin
   Assert(Assigned(FWorkerMessages), 'TAbstractExternalTool.LeaveCriticalSection: FWorkerMessages=Nil.');
-  Sleep(1);
   FWorkerMessages.LeaveCriticalSection;
 end;
 
@@ -2355,8 +2354,8 @@ var
 begin
   if csDestroying in ComponentState then exit;
   Changed:=false;
-  EnterCriticalSection; // Beware: Tool is already in critical section
-  try
+  //EnterCriticalSection; // Beware: Tool is already in critical section !!!
+  //try
     if (FPendingLines=nil) or (FPendingProgressLine=nil) then exit;
     //DebugLn(['TExtToolView.ProcessNewMessages START From=',FirstMsgLine,' To=',Tool.WorkerMessages.Count-1]);
     NewProgressLine:=nil;
@@ -2384,9 +2383,9 @@ begin
       PendingProgressLine.Msg:='';
     end;
     //debugln(['TExtToolView.ProcessNewMessages END Changed=',Changed,' Progress="',ProgressLine.Msg,'"']);
-  finally
-    LeaveCriticalSection;
-  end;
+  //finally       !!!
+  //  LeaveCriticalSection;
+  //end;
 
   if Changed and Assigned(OnChanged) then begin
     // wake up main thread
diff --git a/ide/exttoolsconsole.pas b/ide/exttoolsconsole.pas
index fe80fac922..6638db51a7 100644
--- a/ide/exttoolsconsole.pas
+++ b/ide/exttoolsconsole.pas
@@ -55,6 +55,8 @@ type
   public
     constructor Create(aOwner: TComponent); override;
     destructor Destroy; override;
+    procedure EnterCriticalSection; override;
+    procedure LeaveCriticalSection; override;
   end;
 
   { TExternalToolsConsole }
@@ -193,6 +195,19 @@ begin
   inherited Destroy;
 end;
 
+procedure TExternalToolConsole.EnterCriticalSection;
+begin
+  // A hack to prevent occational crash in LazBuild. Issue #36318, #37883 etc.
+  Sleep(1);                           // ToDo: Find the real bug and fix it.
+  inherited EnterCriticalSection;
+end;
+
+procedure TExternalToolConsole.LeaveCriticalSection;
+begin
+  Sleep(1);
+  inherited LeaveCriticalSection;
+end;
+
 procedure TExternalToolConsole.CreateView;
 // in console mode all output goes unparsed to console
 var