diff --git a/dlls/rpcrt4/tests/server.c b/dlls/rpcrt4/tests/server.c
index b1a5df21259..95bd60b5658 100644
--- a/dlls/rpcrt4/tests/server.c
+++ b/dlls/rpcrt4/tests/server.c
@@ -286,6 +286,18 @@ s_enum_ord(e_t e)
   }
 }
 
+double
+s_square_encue(encue_t *eue)
+{
+  switch (eue->t)
+  {
+  case E1: return eue->tagged_union.i1 * eue->tagged_union.i1;
+  case E2: return eue->tagged_union.f2 * eue->tagged_union.f2;
+  default:
+    return 0.0;
+  }
+}
+
 void
 s_stop(void)
 {
@@ -409,6 +421,7 @@ basic_tests(void)
 static void
 union_tests(void)
 {
+  encue_t eue;
   encu_t eu;
   sun_t su;
   int i;
@@ -437,6 +450,14 @@ union_tests(void)
   eu.t = ENCU_F;
   eu.tagged_union.f = 3.0;
   ok(square_encu(&eu) == 9.0, "RPC square_encu\n");
+
+  eue.t = E1;
+  eue.tagged_union.i1 = 8;
+  ok(square_encue(&eue) == 64.0, "RPC square_encue\n");
+
+  eue.t = E2;
+  eue.tagged_union.f2 = 10.0;
+  ok(square_encue(&eue) == 100.0, "RPC square_encue\n");
 }
 
 static test_list_t *
diff --git a/dlls/rpcrt4/tests/server.idl b/dlls/rpcrt4/tests/server.idl
index 935c4bb33b4..c33f1794ab8 100644
--- a/dlls/rpcrt4/tests/server.idl
+++ b/dlls/rpcrt4/tests/server.idl
@@ -165,9 +165,16 @@ interface IServer
     E4 = 64
   } e_t;
 
+  typedef union encue switch (e_t t)
+  {
+  case E1: int i1;
+  case E2: float f2;
+  } encue_t;
+
   double square_encu(encu_t *eu);
   int sum_parr(int *a[3]);
   int sum_pcarr([size_is(n)] int *a[], int n);
   int enum_ord(e_t e);
+  double square_encue(encue_t *eue);
   void stop(void);
 }
diff --git a/tools/widl/typegen.c b/tools/widl/typegen.c
index f3958dd267f..e8f6d1fe369 100644
--- a/tools/widl/typegen.c
+++ b/tools/widl/typegen.c
@@ -626,6 +626,7 @@ static size_t write_conf_or_var_desc(FILE *file, const func_t *func, const type_
             break;
         case RPC_FC_WCHAR:
         case RPC_FC_SHORT:
+        case RPC_FC_ENUM16:
             param_type = RPC_FC_SHORT;
             param_type_string = "FC_SHORT";
             break;
@@ -634,6 +635,7 @@ static size_t write_conf_or_var_desc(FILE *file, const func_t *func, const type_
             param_type_string = "FC_USHORT";
             break;
         case RPC_FC_LONG:
+        case RPC_FC_ENUM32:
             param_type = RPC_FC_LONG;
             param_type_string = "FC_LONG";
             break;
@@ -1734,12 +1736,26 @@ static size_t write_union_tfs(FILE *file, type_t *type, unsigned int *tfsoff)
     {
         const var_t *sv = LIST_ENTRY(list_head(type->fields), const var_t, entry);
         const type_t *st = sv->type;
-        size_t ss = type_memsize(st, &align);
 
-        print_file(file, 2, "0x%x,\t/* %s */\n", type->type, string_of_type(type->type));
-        print_file(file, 2, "0x%x,\t/* Switch type= %s */\n",
-                   (ss << 4) | st->type, string_of_type(st->type));
-        *tfsoff += 2;
+        switch (st->type)
+        {
+        case RPC_FC_CHAR:
+        case RPC_FC_SMALL:
+        case RPC_FC_USMALL:
+        case RPC_FC_SHORT:
+        case RPC_FC_USHORT:
+        case RPC_FC_LONG:
+        case RPC_FC_ULONG:
+        case RPC_FC_ENUM16:
+        case RPC_FC_ENUM32:
+            print_file(file, 2, "0x%x,\t/* %s */\n", type->type, string_of_type(type->type));
+            print_file(file, 2, "0x%x,\t/* Switch type= %s */\n",
+                       0x40 | st->type, string_of_type(st->type));
+            *tfsoff += 2;
+            break;
+        default:
+            error("union switch type must be an integer, char, or enum\n");
+        }
     }
     print_file(file, 2, "NdrFcShort(0x%x),\t/* %d */\n", size, size);
     print_file(file, 2, "NdrFcShort(0x%x),\t/* %d */\n", nbranch, nbranch);