diff --git a/Generator/CodeWriter/Constants.cs b/Generator/CodeWriter/Constants.cs
index 253809c..8c4a271 100644
--- a/Generator/CodeWriter/Constants.cs
+++ b/Generator/CodeWriter/Constants.cs
@@ -10,21 +10,33 @@ namespace Generator
     {
         private void Constants()
         {
-            /*
-            StartBlock( "internal static class CallbackIdentifiers" );
-            foreach ( var o in def.CallbackIds )
-            {
-                WriteLine( $"public const int {o.Key} = {o.Value};" );
-            }
-            EndBlock();
-
             StartBlock( "internal static class Defines" );
-            foreach ( var o in def.Defines )
+            foreach ( var o in def.Consts )
             {
-                WriteLine( $"internal const string {o.Key} = \"{o.Value}\";" );
+                var type = o.Type.Substring( "const ".Length );
+                type = Cleanup.ConvertType( type );
+
+                var val = o.Val;
+
+                // Don't need to ull in c#
+                if ( val.EndsWith( "ull" ) )
+                    val = val.Replace( "ull", "" );
+
+                val = val.Replace( "uint32", "uint" );
+                val = val.Replace( "16U", "16" );
+                val = val.Replace( "8U", "8" );
+
+                // we're not an actual typedef so can't cast like this
+                val = val.Replace( "( SteamItemInstanceID_t ) ~ 0", "~default(ulong)" );
+
+                // This is defined as 0xffffffff - which is too big for an int
+                // It seems like the loop around is required, so we just hard code it
+                if ( o.Name == "HSERVERQUERY_INVALID" && val == "0xffffffff" )
+                    val = "-1";
+
+                WriteLine( $"internal static readonly {type} {o.Name} = {val};" );
             }
             EndBlock();
-            */
         }
     }
 }
\ No newline at end of file