diff --git a/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/ModelTests.cs b/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/ModelTests.cs
index 44d4611df9..b3867622d5 100644
--- a/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/ModelTests.cs
+++ b/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.Designer/Tests/Designer/ModelTests.cs
@@ -668,31 +668,52 @@ namespace ICSharpCode.WpfDesign.Tests.Designer
 		}
 		
 		[Test]
-		public void AddStringAsResource()
+		public void AddNativeTypeAsResource(object component, string expectedXamlValue)
 		{
 			DesignItem textBlock = CreateCanvasContext("<TextBlock/>");
 			DesignItem canvas = textBlock.Parent;
 			
 			DesignItemProperty canvasResources = canvas.Properties.GetProperty("Resources");
 			
-			DesignItem str = canvas.Services.Component.RegisterComponentForDesigner("stringresource 1");
-			str.Key = "str1";
+			DesignItem componentItem = canvas.Services.Component.RegisterComponentForDesigner(component);
+			componentItem.Key = "res1";
 			
 			Assert.IsTrue(canvasResources.IsCollection);
-			canvasResources.CollectionElements.Add(str);
+			canvasResources.CollectionElements.Add(componentItem);
+			
+			DesignItemProperty prop = textBlock.Properties[TextBlock.TagProperty];
+			prop.SetValue(new StaticResourceExtension());
+			prop.Value.Properties["ResourceKey"].SetValue("res1");
 			
-			textBlock.Properties[TextBlock.TextProperty].SetValue(new StaticResourceExtension());
-			DesignItemProperty prop = textBlock.Properties[TextBlock.TextProperty];
-			prop.Value.Properties["ResourceKey"].SetValue("str1");
+			string typeName = component.GetType().Name;
 			
 			string expectedXaml = "<Canvas.Resources>\n" +
-								  "  <Controls0:String x:Key=\"str1\">stringresource 1</Controls0:String>\n" +
+								  "  <Controls0:" + typeName + " x:Key=\"res1\">" + expectedXamlValue + "</Controls0:" + typeName + ">\n" +
 								  "</Canvas.Resources>\n" +
-								  "<TextBlock Text=\"{StaticResource ResourceKey=str1}\" />";
+								  "<TextBlock Tag=\"{StaticResource ResourceKey=res1}\" />";
 			
 			AssertCanvasDesignerOutput(expectedXaml, textBlock.Context, "xmlns:Controls0=\"clr-namespace:System;assembly=mscorlib\"");
 			AssertLog("");
 		}
+		
+		[Test]
+		public void AddStringAsResource()
+		{
+			AddNativeTypeAsResource("stringresource 1", "stringresource 1");
+		}
+		
+		[Test]
+		public void AddDoubleAsResource()
+		{
+			AddNativeTypeAsResource(0.0123456789d, "0.0123456789");
+		}
+		
+		[Test]
+		public void AddInt32AsResource()
+		{
+			const int i = 123;
+			AddNativeTypeAsResource(i, "123");
+		}
 	}
 	
 	public class MyMultiConverter : IMultiValueConverter
diff --git a/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlDocument.cs b/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlDocument.cs
index 3d79dea7e9..b324fd1bc7 100644
--- a/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlDocument.cs
+++ b/src/AddIns/DisplayBindings/WpfDesign/WpfDesign.XamlDom/Project/XamlDocument.cs
@@ -198,7 +198,7 @@ namespace ICSharpCode.WpfDesign.XamlDom
 			
 			XmlElement xml = _xmlDoc.CreateElement(prefix, elementType.Name, ns);
 
-			if (hasStringConverter && XamlObject.GetContentPropertyName(elementType) != null) {
+			if (hasStringConverter && (XamlObject.GetContentPropertyName(elementType) != null || IsNativeType(instance))) {
 				xml.InnerText = c.ConvertToInvariantString(instance);
 			} else if (instance is Brush && forProperty != null) {  // TODO: this is a hacky fix, because Brush Editor doesn't
 										     // edit Design Items and so we have no XML, only the Brush 
@@ -219,8 +219,6 @@ namespace ICSharpCode.WpfDesign.XamlDom
 						}
 					}
 				}
-			} else if (instance is string) {
-				xml.InnerText = (string)instance;
 			}
 
 			return new XamlObject(this, xml, elementType, instance);
@@ -279,5 +277,10 @@ namespace ICSharpCode.WpfDesign.XamlDom
 
 			return prefix;
 		}
+		
+		bool IsNativeType(object instance)
+		{
+			return instance.GetType().Assembly == typeof(String).Assembly;
+		}
 	}
 }