diff --git a/ide/componentlist.lfm b/ide/componentlist.lfm
index 1396acf35e..f8bc216438 100644
--- a/ide/componentlist.lfm
+++ b/ide/componentlist.lfm
@@ -8,6 +8,7 @@ object ComponentListForm: TComponentListForm
   ClientHeight = 556
   ClientWidth = 338
   KeyPreview = True
+  OnClose = FormClose
   OnKeyDown = FormKeyDown
   Position = poScreenCenter
   LCLVersion = '0.9.31'
diff --git a/ide/componentlist.pas b/ide/componentlist.pas
index bc564d425a..17e2ae5a5a 100644
--- a/ide/componentlist.pas
+++ b/ide/componentlist.pas
@@ -62,6 +62,7 @@ type
     procedure ComponentsListboxDblClick(Sender: TObject);
     procedure ComponentsListboxDrawItem(Control: TWinControl; Index: Integer;
       ARect: TRect; State: TOwnerDrawState);
+    procedure FormClose(Sender: TObject; var CloseAction: TCloseAction);
     procedure TreeCustomDrawItem(Sender: TCustomTreeView;
       Node: TTreeNode; State: TCustomDrawState; var DefaultDraw: Boolean);
     procedure ComponentsListboxKeyDown(Sender: TObject; var Key: Word; Shift: TShiftState);
@@ -360,6 +361,25 @@ begin
   end;
 end;
 
+procedure TComponentListForm.FormClose(Sender: TObject;
+  var CloseAction: TCloseAction);
+begin
+  // Using a dock manager...
+  if Parent<>nil then
+  begin
+    CloseAction := caNone;
+    //todo: helper function in DockManager or IDEDockMaster for closing forms.
+    // Only close the window if it's floating.
+    // AnchorDocking doesn't seem to initialize 'FloatingDockSiteClass' so we can't just check 'Floating'.
+    // Also, AnchorDocking use nested forms, so the check for HostDockSite.Parent.
+    if Assigned(HostDockSite) and (HostDockSite.DockClientCount <= 1)
+      and (HostDockSite is TCustomForm) and (HostDockSite.Parent = nil) then
+    begin
+      TCustomForm(HostDockSite).Close;
+    end;
+  end;
+end;
+
 procedure TComponentListForm.TreeCustomDrawItem(Sender: TCustomTreeView;
   Node: TTreeNode; State: TCustomDrawState; var DefaultDraw: Boolean);
 var