diff --git a/generator/ManagedCallString.cs b/generator/ManagedCallString.cs
index de0ad1b21..3e54fe349 100644
--- a/generator/ManagedCallString.cs
+++ b/generator/ManagedCallString.cs
@@ -28,6 +28,7 @@ namespace GtkSharp.Generation {
 	public class ManagedCallString {
 		
 		IDictionary<Parameter, bool> parms = new Dictionary<Parameter, bool> ();
+		IList<Parameter> dispose_params = new List<Parameter> ();
 		string error_param = null;
 		string user_data_param = null;
 		string destroy_param = null;
@@ -57,6 +58,10 @@ namespace GtkSharp.Generation {
 					special = true;
 
 				this.parms.Add (p, special);
+
+				if (p.IsOwnable) {
+					dispose_params.Add (p);
+				}
 			}
 		}
 
@@ -70,10 +75,18 @@ namespace GtkSharp.Generation {
 			}
 		}
 
+		public bool HasDisposeParam {
+			get { return dispose_params.Count > 0; }
+		}
+
 		public string Unconditional (string indent) {
 			string ret = "";
 			if (error_param != null)
 				ret = indent + error_param + " = IntPtr.Zero;\n";
+
+			foreach (Parameter p in dispose_params) {
+				ret += indent + p.CSType + " my" + p.Name + " = null;\n";
+			}
 			return ret;
 		}
 
@@ -103,6 +116,10 @@ namespace GtkSharp.Generation {
 				}
 			}
 
+			foreach (Parameter p in dispose_params) {
+				ret += indent + "my" + p.Name + " = " + p.FromNative (p.Name) + ";\n";
+			}
+
 			return ret;
 		}
 
@@ -119,7 +136,12 @@ namespace GtkSharp.Generation {
 				if (p.Generatable is CallbackGen) {
 					result [i] += p.Name + "_invoker.Handler";
 				} else {
-					result [i] += (parms [p]) ? "my" + p.Name : p.FromNative (p.Name);
+					if (parms [p] || dispose_params.Contains(p)) {
+						// Parameter was declared and marshalled earlier
+						result [i] +=  "my" + p.Name;
+					} else {
+						result [i] +=  p.FromNative (p.Name);
+					}
 				}
 				i++;
 			}
@@ -150,6 +172,22 @@ namespace GtkSharp.Generation {
 
 			return ret;
 		}
+
+		public string DisposeParams (string indent)
+		{
+			string ret = "";
+
+			foreach (Parameter p in dispose_params) {
+				string name = "my" + p.Name;
+				string disp_name = "disposable_" + p.Name;
+
+				ret += indent + "var " + disp_name + " = " + name + " as IDisposable;\n";
+				ret += indent + "if (" + disp_name + " != null)\n";
+				ret += indent + "\t" + disp_name + ".Dispose ();\n";
+			}
+
+			return ret;
+		}
 	}
 }
 
diff --git a/generator/Parameter.cs b/generator/Parameter.cs
index 981cadee7..02c0ad5c4 100644
--- a/generator/Parameter.cs
+++ b/generator/Parameter.cs
@@ -186,6 +186,12 @@ namespace GtkSharp.Generation {
 			}
 		}
 
+		public bool IsOwnable {
+			get {
+				return this.Generatable is OwnableGen;
+			}
+		}
+
 		public bool Owned {
 			get {
 				return elem.GetAttribute ("owned") == "true";
diff --git a/generator/VirtualMethod.cs b/generator/VirtualMethod.cs
index 878f81a69..901ad02bd 100644
--- a/generator/VirtualMethod.cs
+++ b/generator/VirtualMethod.cs
@@ -98,14 +98,17 @@ namespace GtkSharp.Generation {
 				sw.WriteLine ("\t\t\t\t{0} __obj = GLib.Object.GetObject (inst, false) as {0};", type);
 			}
 
-			sw.Write (call.Setup ("\t\t\t\t"));
-			sw.Write ("\t\t\t\t");
+			string indent = "\t\t\t\t";
 			if (!retval.IsVoid)
-				sw.Write (retval.CSType + " __result = ");
+				sw.WriteLine (indent + retval.CSType + " __result;");
+			sw.Write (call.Setup (indent));
+			sw.Write (indent);
+			if (!retval.IsVoid)
+				sw.Write ("__result = ");
 			if (!this.IsStatic)
 				sw.Write ("__obj.");
 			sw.WriteLine (this.CallString + ";");
-			sw.Write (call.Finish ("\t\t\t\t"));
+			sw.Write (call.Finish (indent));
 			if (!retval.IsVoid)
 				sw.WriteLine ("\t\t\t\treturn " + retval.ToNative ("__result") + ";");
 
@@ -116,6 +119,11 @@ namespace GtkSharp.Generation {
 				sw.WriteLine ("\t\t\t\t// NOTREACHED: above call does not return.");
 				sw.WriteLine ("\t\t\t\tthrow e;");
 			}
+
+			if (call.HasDisposeParam) {
+				sw.WriteLine ("\t\t\t} finally {");
+				sw.Write (call.DisposeParams (indent));
+			}
 			sw.WriteLine ("\t\t\t}");
 			sw.WriteLine ("\t\t}");
 			sw.WriteLine ();