diff --git a/source/dfl/application.d b/source/dfl/application.d
index 6ebb453..cd5ce30 100644
--- a/source/dfl/application.d
+++ b/source/dfl/application.d
@@ -817,7 +817,7 @@ final class Application // docmain
 		}
 		
 		
-		override Dstring toString()
+		override Dstring toString() const
 		{
 			return errBox.text;
 		}
diff --git a/source/dfl/control.d b/source/dfl/control.d
index cd3e8e1..3cc3d0c 100644
--- a/source/dfl/control.d
+++ b/source/dfl/control.d
@@ -2107,7 +2107,7 @@ class Control: DObject, IWindow // docmain
 	
 	
 	///
-	final @property bool isHandleCreated() // getter
+	final @property bool isHandleCreated() const // getter
 	{
 		return hwnd != HWND.init;
 	}
@@ -2744,9 +2744,9 @@ class Control: DObject, IWindow // docmain
 	}
 	
 	
-	private final Dstring _fetchText()
+	private final Dstring _fetchText() const
 	{
-		return dfl.internal.utf.getWindowText(hwnd);
+		return dfl.internal.utf.getWindowText(cast(void*)hwnd);
 	}
 	
 	
@@ -2771,7 +2771,7 @@ class Control: DObject, IWindow // docmain
 	}
 	
 	/// ditto
-	@property Dstring text() // getter
+	@property Dstring text() const // getter
 	{
 		if(isHandleCreated)
 		{
@@ -4228,7 +4228,7 @@ class Control: DObject, IWindow // docmain
 	}
 	
 	
-	override Dstring toString()
+	override Dstring toString() const
 	{
 		return text;
 	}
diff --git a/source/dfl/statusbar.d b/source/dfl/statusbar.d
index 12e9b89..0f7668a 100644
--- a/source/dfl/statusbar.d
+++ b/source/dfl/statusbar.d
@@ -512,7 +512,7 @@ class StatusBar: ControlSuperClass // docmain
 	}
 	
 	/// ditto
-	override @property Dstring text() // getter
+	override @property Dstring text() const // getter
 	{
 		return this._simpletext;
 	}
diff --git a/source/dfl/tabcontrol.d b/source/dfl/tabcontrol.d
index f81acdf..83b7636 100644
--- a/source/dfl/tabcontrol.d
+++ b/source/dfl/tabcontrol.d
@@ -47,7 +47,7 @@ class TabPage: Panel
 	}
 	
 	
-	override Dstring toString()
+	override Dstring toString() const
 	{
 		return text;
 	}
@@ -56,13 +56,13 @@ class TabPage: Panel
 	alias opEquals = Control.opEquals;
 
 	
-	override Dequ opEquals(Object o)
+	override Dequ opEquals(Object o) const
 	{
 		return text == getObjectString(o);
 	}
 
 	
-	Dequ opEquals(Dstring val)
+	Dequ opEquals(Dstring val) const
 	{
 		return text == val;
 	}
@@ -71,13 +71,13 @@ class TabPage: Panel
 	alias opCmp = Control.opCmp;
 
 
-	override int opCmp(Object o)
+	override int opCmp(Object o) const
 	{
 		return stringICmp(text, getObjectString(o));
 	}
 
 
-	int opCmp(Dstring val)
+	int opCmp(Dstring val) const
 	{
 		return stringICmp(text, val);
 	}
diff --git a/source/dfl/textboxbase.d b/source/dfl/textboxbase.d
index 8b86e42..421fe2c 100644
--- a/source/dfl/textboxbase.d
+++ b/source/dfl/textboxbase.d
@@ -575,7 +575,7 @@ abstract class TextBoxBase: ControlSuperClass // docmain
 	}
 	
 	
-	override Dstring toString()
+	override Dstring toString() const
 	{
 		return text; // ?
 	}
diff --git a/source/dfl/treeview.d b/source/dfl/treeview.d
index 5bc779d..449ce77 100644
--- a/source/dfl/treeview.d
+++ b/source/dfl/treeview.d
@@ -447,7 +447,7 @@ class TreeNode: DObject
 	}
 	
 	/// ditto
-	final @property Dstring text() // getter
+	final @property Dstring text() const // getter
 	{
 		return ttext;
 	}
@@ -597,39 +597,39 @@ class TreeNode: DObject
 	}
 	
 	
-	override Dstring toString()
+	override Dstring toString() const
 	{
 		return ttext;
 	}
 	
 	
-	override Dequ opEquals(Object o)
+	override Dequ opEquals(Object o) const
 	{
 		return 0 == stringICmp(ttext, getObjectString(o)); // ?
 	}
 	
-	Dequ opEquals(TreeNode node)
+	Dequ opEquals(TreeNode node) const
 	{
 		return 0 == stringICmp(ttext, node.ttext);
 	}
 	
-	Dequ opEquals(Dstring val)
+	Dequ opEquals(Dstring val) const
 	{
 		return 0 == stringICmp(ttext, val);
 	}
 	
 	
-	override int opCmp(Object o)
+	override int opCmp(Object o) const
 	{
 		return stringICmp(ttext, getObjectString(o)); // ?
 	}
 	
-	int opCmp(TreeNode node)
+	int opCmp(TreeNode node) const
 	{
 		return stringICmp(ttext, node.ttext);
 	}
 	
-	int opCmp(Dstring val)
+	int opCmp(Dstring val) const
 	{
 		return stringICmp(text, val);
 	}