diff --git a/lcl/include/intfbaselcl.inc b/lcl/include/intfbaselcl.inc
index c944939875..bb7455e802 100644
--- a/lcl/include/intfbaselcl.inc
+++ b/lcl/include/intfbaselcl.inc
@@ -26,7 +26,8 @@
 }
 //##apiwiz##sps##   // Do not remove
 
-procedure TWidgetSet.AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent);
+procedure TWidgetSet.AddEventHandler(AHandle: THandle; AFlags: dword; 
+  AEventHandler: TWaitHandleEvent; AData: PtrInt);
 begin
 end;
 
diff --git a/lcl/include/lclintf.inc b/lcl/include/lclintf.inc
index 3c14a9dcdc..e605cd7d2a 100644
--- a/lcl/include/lclintf.inc
+++ b/lcl/include/lclintf.inc
@@ -33,9 +33,10 @@
  ******************************************************************************}
 //##apiwiz##sps##   // Do not remove
 
-procedure AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent);
+procedure AddEventHandler(AHandle: THandle; AFlags: dword; 
+  AEventHandler: TWaitHandleEvent; AData: PtrInt = 0);
 begin
-  WidgetSet.AddEventHandler(AHandle, AFlags, AEventHandler);
+  WidgetSet.AddEventHandler(AHandle, AFlags, AEventHandler, AData);
 end;
 
 procedure AttachMenuToWindow(AMenuObject: TComponent);
diff --git a/lcl/include/lclintfh.inc b/lcl/include/lclintfh.inc
index 3465fb31b6..ac6fde59bf 100644
--- a/lcl/include/lclintfh.inc
+++ b/lcl/include/lclintfh.inc
@@ -37,7 +37,7 @@
  ******************************************************************************}
 //##apiwiz##sps##    // Do not remove
 
-procedure AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
+procedure AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent; AData: PtrInt); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 procedure AttachMenuToWindow(AMenuObject: TComponent); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
 
 procedure CallDefaultWndHandler(Sender: TObject; var Message); {$IFDEF IF_BASE_MEMBER}virtual;{$ENDIF}
diff --git a/lcl/interfacebase.pp b/lcl/interfacebase.pp
index 81421a29a3..fbdfee7195 100644
--- a/lcl/interfacebase.pp
+++ b/lcl/interfacebase.pp
@@ -38,7 +38,7 @@ uses
 
 type
   TApplicationMainLoop = procedure of object;
-  TWaitHandleEvent = procedure(AHandle: THandle; AFlags: dword) of object;
+  TWaitHandleEvent = procedure(AData: PtrInt; AFlags: dword) of object;
 
   { TWidgetSet }
 
diff --git a/lcl/interfaces/gtk/gtklclintf.inc b/lcl/interfaces/gtk/gtklclintf.inc
index 177c62b182..a472ae4900 100644
--- a/lcl/interfaces/gtk/gtklclintf.inc
+++ b/lcl/interfaces/gtk/gtklclintf.inc
@@ -34,12 +34,12 @@ function waithandle_iocallback(source: PGIOChannel; condition: TGIOCondition;
 var
   lEventHandler: PWaitHandleEventHandler absolute data;
 begin
-  lEventHandler^.OnEvent(lEventHandler^.Handle, condition);
+  lEventHandler^.OnEvent(lEventHandler^.UserData, condition);
   result := true;
 end;
 
 procedure TGtkWidgetSet.AddEventHandler(AHandle: THandle; AFlags: dword; 
-  AEventHandler: TWaitHandleEvent);
+  AEventHandler: TWaitHandleEvent; AData: PtrInt);
 var
   giochannel: pgiochannel;
   lEventHandler: PWaitHandleEventHandler;
@@ -48,6 +48,7 @@ begin
   New(lEventHandler);
   giochannel := g_io_channel_unix_new(AHandle);
   lEventHandler^.Handle := AHandle;
+  lEventHandler^.UserData := AData;
   lEventHandler^.GIOChannel := giochannel;
   lEventHandler^.OnEvent := AEventHandler;
   lEventHandler^.GSourceID := g_io_add_watch(giochannel,
diff --git a/lcl/interfaces/gtk/gtklclintfh.inc b/lcl/interfaces/gtk/gtklclintfh.inc
index 448d9cb14c..36e8350cfc 100644
--- a/lcl/interfaces/gtk/gtklclintfh.inc
+++ b/lcl/interfaces/gtk/gtklclintfh.inc
@@ -29,7 +29,8 @@
 }
 
 //##apiwiz##sps##   // Do not remove
-procedure AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent); override;
+procedure AddEventHandler(AHandle: THandle; AFlags: dword; 
+  AEventHandler: TWaitHandleEvent; AData: PtrInt); override;
 function DrawSplitter(DC: HDC; const ARect: TRect; Horizontal: boolean): boolean; override;
 
 function ExtUTF8Out(DC: HDC; X, Y: Integer; Options: Longint; Rect: PRect;
diff --git a/lcl/interfaces/gtk/gtkproc.pp b/lcl/interfaces/gtk/gtkproc.pp
index f628d8853b..8130fc7123 100644
--- a/lcl/interfaces/gtk/gtkproc.pp
+++ b/lcl/interfaces/gtk/gtkproc.pp
@@ -64,6 +64,7 @@ type
     Handle: THandle;
     GIOChannel: pgiochannel;
     GSourceID: guint;
+    UserData: PtrInt;
     OnEvent: TWaitHandleEvent;
     NextHandler: PWaitHandleEventHandler;
   end;
diff --git a/lcl/interfaces/win32/win32int.pp b/lcl/interfaces/win32/win32int.pp
index c916b85608..f9e8551ab9 100644
--- a/lcl/interfaces/win32/win32int.pp
+++ b/lcl/interfaces/win32/win32int.pp
@@ -101,6 +101,11 @@ Type
     dwICC: dword;
   end;
 
+  TWaitHandler = record
+    UserData: PtrInt;
+    OnEvent: TWaitHandleEvent;
+  end;
+
   { Win32 interface-object class }
   TWin32WidgetSet = Class(TWidgetSet)
   Private
@@ -124,7 +129,7 @@ Type
 
     FWaitHandleCount: dword;
     FWaitHandles: array of HANDLE;
-    FWaitHandleCallbacks: array of TWaitHandleEvent;
+    FWaitHandlers: array of TWaitHandler;
 
     FThemesActive: boolean;
     FThemeLibrary: HMODULE;
diff --git a/lcl/interfaces/win32/win32lclintf.inc b/lcl/interfaces/win32/win32lclintf.inc
index d29c08f838..ec94c8bcf7 100644
--- a/lcl/interfaces/win32/win32lclintf.inc
+++ b/lcl/interfaces/win32/win32lclintf.inc
@@ -29,7 +29,8 @@
 
 //##apiwiz##sps##   // Do not remove
 
-procedure TWin32WidgetSet.AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent);
+procedure TWin32WidgetSet.AddEventHandler(AHandle: THandle; AFlags: dword; 
+  AEventHandler: TWaitHandleEvent; AData: PtrInt);
 var
   listlen: dword;
 begin
@@ -38,10 +39,11 @@ begin
   begin
     inc(listlen, 16);
     SetLength(FWaitHandles, listlen);
-    SetLength(FWaitHandleCallbacks, listlen);
+    SetLength(FWaitHandlers, listlen);
   end;
   FWaitHandles[FWaitHandleCount] := AHandle;
-  FWaitHandleCallbacks[FWaitHandleCount] := AEventHandler;
+  FWaitHandlers[FWaitHandleCount].UserData := AData;
+  FWaitHandlers[FWaitHandleCount].OnEvent := AEventHandler;
   Inc(FWaitHandleCount);
 end;
 
@@ -56,7 +58,7 @@ begin
       if FWaitHandleCount >= 2 then
       begin
         FWaitHandles[I] := FWaitHandles[FWaitHandleCount-1];
-        FWaitHandleCallbacks[I] := FWaitHandleCallbacks[FWaitHandleCount-1];
+        FWaitHandlers[I] := FWaitHandlers[FWaitHandleCount-1];
       end;
       Dec(FWaitHandleCount);
       exit;
diff --git a/lcl/interfaces/win32/win32lclintfh.inc b/lcl/interfaces/win32/win32lclintfh.inc
index 2ac13cb042..2d8d91296a 100644
--- a/lcl/interfaces/win32/win32lclintfh.inc
+++ b/lcl/interfaces/win32/win32lclintfh.inc
@@ -29,7 +29,8 @@
 
 //##apiwiz##sps##   // Do not remove
 
-procedure AddEventHandler(AHandle: THandle; AFlags: dword; AEventHandler: TWaitHandleEvent); override;
+procedure AddEventHandler(AHandle: THandle; AFlags: dword; 
+  AEventHandler: TWaitHandleEvent; AData: PtrInt); override;
 
 procedure DrawArrow(Arrow: TComponent; Canvas: TPersistent); override;
 
diff --git a/lcl/interfaces/win32/win32object.inc b/lcl/interfaces/win32/win32object.inc
index 5fae6d6cfa..9fe9fa107f 100644
--- a/lcl/interfaces/win32/win32object.inc
+++ b/lcl/interfaces/win32/win32object.inc
@@ -335,7 +335,7 @@ begin
     if (WAIT_OBJECT_0 <= retVal) and (retVal < WAIT_OBJECT_0 + FWaitHandleCount) then
     begin
       index := retVal-WAIT_OBJECT_0;
-      FWaitHandleCallbacks[index](FWaitHandles[index], 0);
+      FWaitHandlers[index].OnEvent(FWaitHandlers[index].UserData, 0);
     end else if retVal = WAIT_OBJECT_0 + FWaitHandleCount then
       done := true;
   until done;