diff --git a/tools/widl/client.c b/tools/widl/client.c
index 93bf1fc2c54..673b9188357 100644
--- a/tools/widl/client.c
+++ b/tools/widl/client.c
@@ -483,7 +483,7 @@ static void write_client_ifaces(const statement_list_t *stmts, int expr_eval_rou
                 write_stubdescdecl(iface);
                 write_function_stubs(iface, proc_offset);
 
-                print_client("#if !defined(__RPC_WIN32__)\n");
+                print_client("#if !defined(__RPC_WIN%u__)\n", pointer_size == 8 ? 64 : 32);
                 print_client("#error  Invalid build platform for this stub.\n");
                 print_client("#endif\n");
 
@@ -496,22 +496,11 @@ static void write_client_ifaces(const statement_list_t *stmts, int expr_eval_rou
     }
 }
 
-void write_client(const statement_list_t *stmts)
+static void write_client_routines(const statement_list_t *stmts)
 {
     unsigned int proc_offset = 0;
     int expr_eval_routines;
 
-    if (!do_client)
-        return;
-    if (do_everything && !need_stub_files(stmts))
-        return;
-
-    init_client();
-    if (!client)
-        return;
-
-    pointer_size = sizeof(void*);
-
     write_formatstringsdecl(client, indent, stmts, need_stub);
     expr_eval_routines = write_expr_eval_routines(client, client_token);
     if (expr_eval_routines)
@@ -524,6 +513,39 @@ void write_client(const statement_list_t *stmts)
 
     write_procformatstring(client, stmts, need_stub);
     write_typeformatstring(client, stmts, need_stub);
+}
+
+void write_client(const statement_list_t *stmts)
+{
+    if (!do_client)
+        return;
+    if (do_everything && !need_stub_files(stmts))
+        return;
+
+    init_client();
+    if (!client)
+        return;
+
+    if (do_win32 && do_win64)
+    {
+        fprintf(client, "\n#ifndef _WIN64\n\n");
+        pointer_size = 4;
+        write_client_routines( stmts );
+        fprintf(client, "\n#else /* _WIN64 */\n\n");
+        pointer_size = 8;
+        write_client_routines( stmts );
+        fprintf(client, "\n#endif /* _WIN64 */\n");
+    }
+    else if (do_win32)
+    {
+        pointer_size = 4;
+        write_client_routines( stmts );
+    }
+    else if (do_win64)
+    {
+        pointer_size = 8;
+        write_client_routines( stmts );
+    }
 
     fclose(client);
 }
diff --git a/tools/widl/parser.y b/tools/widl/parser.y
index da1d7b32a23..4d44e2ce0b9 100644
--- a/tools/widl/parser.y
+++ b/tools/widl/parser.y
@@ -1366,6 +1366,13 @@ void set_all_tfswrite(int val)
     node->data.tfswrite = val;
 }
 
+void clear_all_offsets(void)
+{
+  type_pool_node_t *node;
+  LIST_FOR_EACH_ENTRY(node, &type_pool, type_pool_node_t, link)
+    node->data.typestring_offset = node->data.ptrdesc = 0;
+}
+
 type_t *make_type(unsigned char type, type_t *ref)
 {
   type_t *t = alloc_type();
diff --git a/tools/widl/proxy.c b/tools/widl/proxy.c
index fdc6cd6f017..7bb6acdb538 100644
--- a/tools/widl/proxy.c
+++ b/tools/widl/proxy.c
@@ -741,21 +741,10 @@ static type_t **sort_interfaces( const statement_list_t *stmts, int *count )
     return ifaces;
 }
 
-void write_proxies(const statement_list_t *stmts)
+static void write_proxy_routines(const statement_list_t *stmts)
 {
   int expr_eval_routines;
-  char *file_id = proxy_token;
-  int i, count, have_baseiid;
   unsigned int proc_offset = 0;
-  type_t **interfaces;
-
-  if (!do_proxies) return;
-  if (do_everything && !need_proxy_file(stmts)) return;
-
-  init_proxy(stmts);
-  if(!proxy) return;
-
-  pointer_size = sizeof(void*);
 
   write_formatstringsdecl(proxy, indent, stmts, need_proxy);
   write_stubdescproto();
@@ -767,13 +756,48 @@ void write_proxies(const statement_list_t *stmts)
   write_user_quad_list(proxy);
   write_stubdesc(expr_eval_routines);
 
-  print_proxy( "#if !defined(__RPC_WIN32__)\n");
+  print_proxy( "#if !defined(__RPC_WIN%u__)\n", pointer_size == 8 ? 64 : 32);
   print_proxy( "#error Currently only Wine and WIN32 are supported.\n");
   print_proxy( "#endif\n");
   print_proxy( "\n");
   write_procformatstring(proxy, stmts, need_proxy);
   write_typeformatstring(proxy, stmts, need_proxy);
 
+}
+
+void write_proxies(const statement_list_t *stmts)
+{
+  char *file_id = proxy_token;
+  int i, count, have_baseiid;
+  type_t **interfaces;
+
+  if (!do_proxies) return;
+  if (do_everything && !need_proxy_file(stmts)) return;
+
+  init_proxy(stmts);
+  if(!proxy) return;
+
+  if (do_win32 && do_win64)
+  {
+      fprintf(proxy, "\n#ifndef _WIN64\n\n");
+      pointer_size = 4;
+      write_proxy_routines( stmts );
+      fprintf(proxy, "\n#else /* _WIN64 */\n\n");
+      pointer_size = 8;
+      write_proxy_routines( stmts );
+      fprintf(proxy, "#endif /* _WIN64 */\n\n");
+  }
+  else if (do_win32)
+  {
+      pointer_size = 4;
+      write_proxy_routines( stmts );
+  }
+  else if (do_win64)
+  {
+      pointer_size = 8;
+      write_proxy_routines( stmts );
+  }
+
   interfaces = sort_interfaces(stmts, &count);
   fprintf(proxy, "static const CInterfaceProxyVtbl* const _%s_ProxyVtblList[] =\n", file_id);
   fprintf(proxy, "{\n");
diff --git a/tools/widl/server.c b/tools/widl/server.c
index 0edee901235..20d0e7e43c7 100644
--- a/tools/widl/server.c
+++ b/tools/widl/server.c
@@ -424,7 +424,7 @@ static void write_server_stmts(const statement_list_t *stmts, int expr_eval_rout
 
                 write_function_stubs(iface, proc_offset);
 
-                print_server("#if !defined(__RPC_WIN32__)\n");
+                print_server("#if !defined(__RPC_WIN%u__)\n", pointer_size == 8 ? 64 : 32);
                 print_server("#error  Invalid build platform for this stub.\n");
                 print_server("#endif\n");
 
@@ -436,22 +436,11 @@ static void write_server_stmts(const statement_list_t *stmts, int expr_eval_rout
     }
 }
 
-void write_server(const statement_list_t *stmts)
+static void write_server_routines(const statement_list_t *stmts)
 {
     unsigned int proc_offset = 0;
     int expr_eval_routines;
 
-    if (!do_server)
-        return;
-    if (do_everything && !need_stub_files(stmts))
-        return;
-
-    init_server();
-    if (!server)
-        return;
-
-    pointer_size = sizeof(void*);
-
     write_formatstringsdecl(server, indent, stmts, need_stub);
     expr_eval_routines = write_expr_eval_routines(server, server_token);
     if (expr_eval_routines)
@@ -464,6 +453,39 @@ void write_server(const statement_list_t *stmts)
 
     write_procformatstring(server, stmts, need_stub);
     write_typeformatstring(server, stmts, need_stub);
+}
+
+void write_server(const statement_list_t *stmts)
+{
+    if (!do_server)
+        return;
+    if (do_everything && !need_stub_files(stmts))
+        return;
+
+    init_server();
+    if (!server)
+        return;
+
+    if (do_win32 && do_win64)
+    {
+        fprintf(server, "\n#ifndef _WIN64\n\n");
+        pointer_size = 4;
+        write_server_routines( stmts );
+        fprintf(server, "\n#else /* _WIN64 */\n\n");
+        pointer_size = 8;
+        write_server_routines( stmts );
+        fprintf(server, "\n#endif /* _WIN64 */\n");
+    }
+    else if (do_win32)
+    {
+        pointer_size = 4;
+        write_server_routines( stmts );
+    }
+    else if (do_win64)
+    {
+        pointer_size = 8;
+        write_server_routines( stmts );
+    }
 
     fclose(server);
 }
diff --git a/tools/widl/typegen.c b/tools/widl/typegen.c
index a452bdfc519..ed9430ce185 100644
--- a/tools/widl/typegen.c
+++ b/tools/widl/typegen.c
@@ -572,6 +572,8 @@ static void write_formatdesc(FILE *f, int indent, const char *str)
 
 void write_formatstringsdecl(FILE *f, int indent, const statement_list_t *stmts, type_pred_t pred)
 {
+    clear_all_offsets();
+
     print_file(f, indent, "#define TYPE_FORMAT_STRING_SIZE %d\n",
                get_size_typeformatstring(stmts, pred));
 
diff --git a/tools/widl/widltypes.h b/tools/widl/widltypes.h
index d00a73255ca..4f1fc1c9116 100644
--- a/tools/widl/widltypes.h
+++ b/tools/widl/widltypes.h
@@ -396,6 +396,7 @@ void check_for_additional_prototype_types(const var_list_t *list);
 void init_types(void);
 type_t *alloc_type(void);
 void set_all_tfswrite(int val);
+void clear_all_offsets(void);
 
 type_t *duptype(type_t *t, int dupname);
 type_t *alias(type_t *t, const char *name);