diff --git a/ChangeLog b/ChangeLog
index 05fbfb5bb..6d2d337b4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-08  Christian Hoff  <christian_hoff@gmx.net>
+
+	* generator/Signal.cs: Fix indexing of the signal arguments array for
+	"out" and "ref" parameters.  [Fixes #508572]
+
 2009-05-28  Aaron Bockover  <abockover@novell.com>
 
 	* generator/EnumGen.cs: Fix enum generator to properly parse integer
diff --git a/generator/Signal.cs b/generator/Signal.cs
index b2ee0aadf..f5def07f6 100644
--- a/generator/Signal.cs
+++ b/generator/Signal.cs
@@ -179,9 +179,9 @@ namespace GtkSharp.Generation {
 						sw.WriteLine("\t\t\t\targs.Args[" + idx + "] = " + p.FromNative ("arg" + idx)  + ";");
 				}
 				if (igen is StructBase && p.PassAs == "ref")
-					finish += "\t\t\t\tif (arg" + idx + " != IntPtr.Zero) System.Runtime.InteropServices.Marshal.StructureToPtr (args.Args[" + (idx-1) + "], arg" + idx + ", false);\n";
+					finish += "\t\t\t\tif (arg" + idx + " != IntPtr.Zero) System.Runtime.InteropServices.Marshal.StructureToPtr (args.Args[" + idx + "], arg" + idx + ", false);\n";
 				else if (p.PassAs != "")
-					finish += "\t\t\t\targ" + idx + " = " + igen.ToNativeReturn ("((" + p.CSType + ")args.Args[" + (idx - 1) + "])") + ";\n";
+					finish += "\t\t\t\targ" + idx + " = " + igen.ToNativeReturn ("((" + p.CSType + ")args.Args[" + idx + "])") + ";\n";
 			}
 			return finish;
 		}