diff --git a/Makefile.include b/Makefile.include
index 61b93ab69..eb97d9133 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -17,7 +17,7 @@ DISTCLEANFILES = $(ASSEMBLY).config
 POLICY_ASSEMBLIES = $(addsuffix .$(ASSEMBLY), $(addprefix policy., $(POLICY_VERSIONS)))
 POLICY_CONFIGS = $(addsuffix .config, $(addprefix policy., $(POLICY_VERSIONS)))
 
-EXTRA_DIST = $(RAW_API) $(SYMBOLS) $(ASSEMBLY).config.in $(METADATA) $(customs) $(sources) $(add_dist)
+EXTRA_DIST = $(RAW_API) $(SYMBOLS) $(ASSEMBLY).config.in $(METADATA) $(sources) $(add_dist)
 
 build_symbols = $(addprefix --symbols=$(srcdir)/, $(SYMBOLS))
 
@@ -29,14 +29,13 @@ $(API): $(METADATA) $(RAW_API) $(SYMBOLS) $(top_builddir)/parser/gapi-fixup.exe
 		$(RUNTIME) $(top_builddir)/parser/gapi-fixup.exe --api=$(API) --metadata=$(srcdir)/$(METADATA) $(build_symbols); \
 	fi
 
-build_customs = $(addprefix $(srcdir)/, $(customs))
 api_includes = $(addprefix -I:, $(INCLUDE_API))
 
-generated-stamp: $(API) $(INCLUDE_API) $(top_builddir)/generator/gapi_codegen.exe $(build_customs)
+generated-stamp: $(API) $(INCLUDE_API) $(top_builddir)/generator/gapi_codegen.exe
 	rm -f generated/* &&	\
 	$(RUNTIME) $(top_builddir)/generator/gapi_codegen.exe --generate $(API) \
 	$(api_includes)	\
-	--outdir=generated --customdir=$(srcdir) --assembly-name=$(ASSEMBLY_NAME)	\
+	--outdir=generated --assembly-name=$(ASSEMBLY_NAME)	\
 	--gluelib-name=$(pkg)sharpglue-3 --glue-filename=glue/generated.c		\
 	--glue-includes=$(glue_includes)						\
 	&& touch generated-stamp
diff --git a/generator/BoxedGen.cs b/generator/BoxedGen.cs
index 28656f23f..a0a3e38e3 100644
--- a/generator/BoxedGen.cs
+++ b/generator/BoxedGen.cs
@@ -72,9 +72,8 @@ namespace GtkSharp.Generation {
 			}
 
 			sw.WriteLine ("#endregion");
-                        AppendCustom(sw, gen_info.CustomDir);
-                        sw.WriteLine ("\t}");
-                        sw.WriteLine ("}");
+			sw.WriteLine ("\t}");
+			sw.WriteLine ("}");
 			sw.Close ();
 			gen_info.Writer = null;
 			Statistics.BoxedCount++;
diff --git a/generator/ClassGen.cs b/generator/ClassGen.cs
index 299393cf0..69841f6d4 100644
--- a/generator/ClassGen.cs
+++ b/generator/ClassGen.cs
@@ -81,7 +81,6 @@ namespace GtkSharp.Generation {
 			GenMethods (gen_info, null, null);
 			
 			sw.WriteLine ("#endregion");
-			AppendCustom(sw, gen_info.CustomDir);
 
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
diff --git a/generator/CodeGenerator.cs b/generator/CodeGenerator.cs
index f45c7a0ef..3be4ce273 100644
--- a/generator/CodeGenerator.cs
+++ b/generator/CodeGenerator.cs
@@ -37,7 +37,6 @@ namespace GtkSharp.Generation {
 
 			bool generate = false;
 			string dir = "";
-			string custom_dir = "";
 			string assembly_name = "";
 			string glue_filename = "";
 			string glue_includes = "";
@@ -46,6 +45,10 @@ namespace GtkSharp.Generation {
 			SymbolTable table = SymbolTable.Table;
 			ArrayList gens = new ArrayList ();
 			foreach (string arg in args) {
+				if (arg.StartsWith ("--customdir=")) {
+					Console.WriteLine ("Using .custom files is not supported anymore, use partial classes instead.");
+					return 0;
+				}
 				string filename = arg;
 				if (arg == "--generate") {
 					generate = true;
@@ -60,10 +63,6 @@ namespace GtkSharp.Generation {
 					generate = false;
 					dir = arg.Substring (9);
 					continue;
-				} else if (arg.StartsWith ("--customdir=")) {
-					generate = false;
-					custom_dir = arg.Substring (12);
-					continue;
 				} else if (arg.StartsWith ("--assembly-name=")) {
 					generate = false;
 					assembly_name = arg.Substring (16);
@@ -101,7 +100,7 @@ namespace GtkSharp.Generation {
 
 			GenerationInfo gen_info = null;
 			if (dir != "" || assembly_name != "" || glue_filename != "" || glue_includes != "" || gluelib_name != "")
-				gen_info = new GenerationInfo (dir, custom_dir, assembly_name, glue_filename, glue_includes, gluelib_name);
+				gen_info = new GenerationInfo (dir, assembly_name, glue_filename, glue_includes, gluelib_name);
 			
 			foreach (IGeneratable gen in gens) {
 				if (gen_info == null)
diff --git a/generator/GObjectVM.cs b/generator/GObjectVM.cs
index a5e4555fd..8aac614d8 100644
--- a/generator/GObjectVM.cs
+++ b/generator/GObjectVM.cs
@@ -190,7 +190,7 @@ namespace GtkSharp.Generation {
 			sw.WriteLine ("\t\t\t{0}Internal{1} ({2});", retval.IsVoid ? "" : "return ", this.Name, Signature.GetCallString (false));
 			sw.WriteLine ("\t\t}");
 			sw.WriteLine ();
-			// This method is to be invoked from existing VM implementations in the .customs
+			// This method is to be invoked from existing VM implementations in the custom code
 			sw.WriteLine ("\t\tprivate {0} Internal{1} ({2})", retval.CSType, this.Name, Signature.ToString ());
 			sw.WriteLine ("\t\t{");
 		}
diff --git a/generator/GenBase.cs b/generator/GenBase.cs
index 1e4011ce0..378e3c845 100644
--- a/generator/GenBase.cs
+++ b/generator/GenBase.cs
@@ -94,26 +94,6 @@ namespace GtkSharp.Generation {
 			}
 		}
 
-		protected void AppendCustom (StreamWriter sw, string custom_dir)
-		{
-			AppendCustom (sw, custom_dir, Name);
-		}
-
-		protected void AppendCustom (StreamWriter sw, string custom_dir, string type_name)
-		{
-			char sep = Path.DirectorySeparatorChar;
-			string custom = custom_dir + sep + type_name + ".custom";
-			if (File.Exists(custom)) {
-				sw.WriteLine ("#region Customized extensions");
-				sw.WriteLine ("#line 1 \"" + type_name + ".custom\"");
-				FileStream custstream = new FileStream(custom, FileMode.Open, FileAccess.Read);
-				StreamReader sr = new StreamReader(custstream);
-				sw.WriteLine (sr.ReadToEnd ());
-				sw.WriteLine ("#endregion");
-				sr.Close ();
-			}
-		}
-
 		public abstract string CallByName (string var);
 
 		public abstract string FromNative (string var);
diff --git a/generator/GenerationInfo.cs b/generator/GenerationInfo.cs
index a7fc74ee3..3535a62c8 100644
--- a/generator/GenerationInfo.cs
+++ b/generator/GenerationInfo.cs
@@ -29,7 +29,6 @@ namespace GtkSharp.Generation {
 	public class GenerationInfo {
 		
 		string dir;
-		string custom_dir;
 		string assembly_name;
 		string gluelib_name;
 		bool glue_enabled;
@@ -41,16 +40,14 @@ namespace GtkSharp.Generation {
 			string ns_name = ns.GetAttribute ("name");
 			char sep = Path.DirectorySeparatorChar;
 			dir = ".." + sep + ns_name.ToLower () + sep + "generated";
-			custom_dir = ".." + sep + ns_name.ToLower ();
 			assembly_name = ns_name.ToLower () + "-sharp";
 		}
 
-		public GenerationInfo (string dir, string assembly_name) : this (dir, dir, assembly_name, "", "", "") {}
+		public GenerationInfo (string dir, string assembly_name) : this (dir, assembly_name, "", "", "") {}
 
-		public GenerationInfo (string dir, string custom_dir, string assembly_name, string glue_filename, string glue_includes, string gluelib_name)
+		public GenerationInfo (string dir, string assembly_name, string glue_filename, string glue_includes, string gluelib_name)
 		{
 			this.dir = dir;
-			this.custom_dir = custom_dir;
 			this.assembly_name = assembly_name;
 			this.gluelib_name = gluelib_name;
 			InitializeGlue (glue_filename, glue_includes, gluelib_name);
@@ -90,12 +87,6 @@ namespace GtkSharp.Generation {
 			}
 		}
 
-		public string CustomDir {
-			get {
-				return custom_dir;
-			}
-		}
-
 		public string Dir {
 			get {
 				return dir;
diff --git a/generator/InterfaceGen.cs b/generator/InterfaceGen.cs
index 6bf34d95c..9978c7ae4 100644
--- a/generator/InterfaceGen.cs
+++ b/generator/InterfaceGen.cs
@@ -270,8 +270,6 @@ namespace GtkSharp.Generation {
 
 			sw.WriteLine ("#endregion");
 
-			AppendCustom (sw, gen_info.CustomDir, Name + "Adapter");
-
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
 			sw.Close ();
@@ -320,7 +318,6 @@ namespace GtkSharp.Generation {
 				sw.WriteLine ("\t\t[GLib.Property (\"" + prop.CName + "\")]");
 				prop.GenerateDecl (sw, "\t\t");
 			}
-			AppendCustom (sw, gen_info.CustomDir, Name + "Implementor");
 
 			sw.WriteLine ("\t}");
 		}
@@ -353,8 +350,6 @@ namespace GtkSharp.Generation {
 			foreach (Property prop in props.Values)
 				prop.GenerateDecl (sw, "\t\t");
 
-			AppendCustom (sw, gen_info.CustomDir);
-
 			sw.WriteLine ("\t}");
 			GenerateImplementorIface (gen_info);
 			sw.WriteLine ("#endregion");
diff --git a/generator/ObjectGen.cs b/generator/ObjectGen.cs
index 8fe27b6f3..e7ef13d57 100644
--- a/generator/ObjectGen.cs
+++ b/generator/ObjectGen.cs
@@ -239,7 +239,6 @@ namespace GtkSharp.Generation {
 			}
 
 			sw.WriteLine ("#endregion");
-			AppendCustom (sw, gen_info.CustomDir);
 
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
diff --git a/generator/OpaqueGen.cs b/generator/OpaqueGen.cs
index eb56c945c..89b175c3f 100644
--- a/generator/OpaqueGen.cs
+++ b/generator/OpaqueGen.cs
@@ -183,8 +183,6 @@ namespace GtkSharp.Generation {
 			}
 #endif
 			sw.WriteLine ("#endregion");
-			
-			AppendCustom(sw, gen_info.CustomDir);
 
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
diff --git a/generator/StructBase.cs b/generator/StructBase.cs
index 591a06e1a..9a0b380c7 100644
--- a/generator/StructBase.cs
+++ b/generator/StructBase.cs
@@ -224,8 +224,7 @@ namespace GtkSharp.Generation {
 				return;
 
 			sw.WriteLine ("#endregion");
-			AppendCustom(sw, gen_info.CustomDir);
-			
+
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
 			sw.Close ();
diff --git a/generator/StructGen.cs b/generator/StructGen.cs
index be38c14fb..e3da30392 100644
--- a/generator/StructGen.cs
+++ b/generator/StructGen.cs
@@ -41,7 +41,6 @@ namespace GtkSharp.Generation {
 				sw.WriteLine ("\t\t}");
 			}
 			sw.WriteLine ("#endregion");
-			AppendCustom (sw, gen_info.CustomDir);
 			sw.WriteLine ("\t}");
 			sw.WriteLine ("}");
 			sw.Close ();