diff --git a/src/goto-programs/class_identifier.cpp b/src/goto-programs/class_identifier.cpp
index 05fd4c989ce..3ab1e8286a8 100644
--- a/src/goto-programs/class_identifier.cpp
+++ b/src/goto-programs/class_identifier.cpp
@@ -28,8 +28,8 @@ static exprt build_class_identifier(
 
   while(1)
   {
-    const typet &type=ns.follow(e.type());
-    const struct_typet &struct_type=to_struct_type(type);
+    const struct_typet &struct_type =
+      ns.follow_tag(to_struct_tag_type(e.type()));
     const struct_typet::componentst &components=struct_type.components();
     INVARIANT(!components.empty(), "class structs cannot be empty");
 
@@ -85,7 +85,8 @@ void set_class_identifier(
   const namespacet &ns,
   const struct_tag_typet &class_type)
 {
-  const struct_typet &struct_type=to_struct_type(ns.follow(expr.type()));
+  const struct_typet &struct_type =
+    ns.follow_tag(to_struct_tag_type(expr.type()));
   const struct_typet::componentst &components=struct_type.components();
 
   if(components.empty())
diff --git a/src/goto-programs/destructor.cpp b/src/goto-programs/destructor.cpp
index 29ff573929b..9ad197dc572 100644
--- a/src/goto-programs/destructor.cpp
+++ b/src/goto-programs/destructor.cpp
@@ -38,9 +38,13 @@ code_function_callt get_destructor(
         {
           const typet &arg_type=code_type.parameters().front().type();
 
+          if(arg_type.id() != ID_pointer)
+            continue;
+
+          const typet &base_type = to_pointer_type(arg_type).base_type();
           if(
-            arg_type.id() == ID_pointer &&
-            ns.follow(to_pointer_type(arg_type).base_type()) == type)
+            base_type.id() == ID_struct_tag &&
+            ns.follow_tag(to_struct_tag_type(base_type)) == type)
           {
             const symbol_exprt symbol_expr(op.get(ID_name), op.type());
             return code_function_callt(symbol_expr);
diff --git a/src/goto-programs/graphml_witness.cpp b/src/goto-programs/graphml_witness.cpp
index 50aa2e3bcb2..31a6e8c2ac3 100644
--- a/src/goto-programs/graphml_witness.cpp
+++ b/src/goto-programs/graphml_witness.cpp
@@ -132,10 +132,13 @@ std::string graphml_witnesst::convert_assign_rec(
       return convert_assign_rec(identifier, tmp);
     }
 
-    const struct_union_typet &type=
-      to_struct_union_type(ns.follow(assign.lhs().type()));
-    const struct_union_typet::componentst &components=
-      type.components();
+    const typet &lhs_type = assign.lhs().type();
+    const struct_union_typet::componentst &components =
+      lhs_type.id() == ID_struct_tag
+        ? ns.follow_tag(to_struct_tag_type(lhs_type)).components()
+      : lhs_type.id() == ID_union_tag
+        ? ns.follow_tag(to_union_tag_type(lhs_type)).components()
+        : to_struct_union_type(lhs_type).components();
 
     exprt::operandst::const_iterator it=
       assign.rhs().operands().begin();
diff --git a/src/goto-programs/interpreter.cpp b/src/goto-programs/interpreter.cpp
index 7761d4d091f..29d0f766f56 100644
--- a/src/goto-programs/interpreter.cpp
+++ b/src/goto-programs/interpreter.cpp
@@ -424,11 +424,11 @@ void interpretert::execute_decl()
 struct_typet::componentt
 interpretert::get_component(const typet &object_type, const mp_integer &offset)
 {
-  const typet real_type = ns.follow(object_type);
-  if(real_type.id()!=ID_struct)
+  if(object_type.id() != ID_struct_tag)
     throw "request for member of non-struct";
 
-  const struct_typet &struct_type=to_struct_type(real_type);
+  const struct_typet &struct_type =
+    ns.follow_tag(to_struct_tag_type(object_type));
   const struct_typet::componentst &components=struct_type.components();
 
   mp_integer tmp_offset=offset;
@@ -460,11 +460,10 @@ exprt interpretert::get_value(
   const mp_integer &offset,
   bool use_non_det)
 {
-  const typet real_type=ns.follow(type);
-  if(real_type.id()==ID_struct)
+  if(type.id() == ID_struct_tag)
   {
-    struct_exprt result({}, real_type);
-    const struct_typet &struct_type=to_struct_type(real_type);
+    struct_exprt result({}, type);
+    const struct_typet &struct_type = ns.follow_tag(to_struct_tag_type(type));
     const struct_typet::componentst &components=struct_type.components();
 
     // Retrieve the values for the individual members
@@ -482,10 +481,10 @@ exprt interpretert::get_value(
 
     return std::move(result);
   }
-  else if(real_type.id()==ID_array)
+  else if(type.id() == ID_array)
   {
     // Get size of array
-    array_exprt result({}, to_array_type(real_type));
+    array_exprt result({}, to_array_type(type));
     const exprt &size_expr = to_array_type(type).size();
     mp_integer subtype_size = get_size(to_array_type(type).element_type());
     mp_integer count;
@@ -526,13 +525,12 @@ exprt interpretert::get_value(
   mp_vectort &rhs,
   const mp_integer &offset)
 {
-  const typet real_type=ns.follow(type);
   PRECONDITION(!rhs.empty());
 
-  if(real_type.id()==ID_struct)
+  if(type.id() == ID_struct_tag)
   {
-    struct_exprt result({}, real_type);
-    const struct_typet &struct_type=to_struct_type(real_type);
+    struct_exprt result({}, type);
+    const struct_typet &struct_type = ns.follow_tag(to_struct_tag_type(type));
     const struct_typet::componentst &components=struct_type.components();
 
     // Retrieve the values for the individual members
@@ -548,10 +546,10 @@ exprt interpretert::get_value(
     }
     return std::move(result);
   }
-  else if(real_type.id()==ID_array)
+  else if(type.id() == ID_array)
   {
-    array_exprt result({}, to_array_type(real_type));
-    const exprt &size_expr = to_array_type(real_type).size();
+    array_exprt result({}, to_array_type(type));
+    const exprt &size_expr = to_array_type(type).size();
 
     // Get size of array
     mp_integer subtype_size = get_size(to_array_type(type).element_type());
@@ -576,34 +574,34 @@ exprt interpretert::get_value(
     }
     return std::move(result);
   }
-  else if(real_type.id()==ID_floatbv)
+  else if(type.id() == ID_floatbv)
   {
     ieee_floatt f(to_floatbv_type(type));
     f.unpack(rhs[numeric_cast_v<std::size_t>(offset)]);
     return f.to_expr();
   }
-  else if(real_type.id()==ID_fixedbv)
+  else if(type.id() == ID_fixedbv)
   {
     fixedbvt f;
     f.from_integer(rhs[numeric_cast_v<std::size_t>(offset)]);
     return f.to_expr();
   }
-  else if(real_type.id()==ID_bool)
+  else if(type.id() == ID_bool)
   {
     if(rhs[numeric_cast_v<std::size_t>(offset)] != 0)
       return true_exprt();
     else
       false_exprt();
   }
-  else if(real_type.id()==ID_c_bool)
+  else if(type.id() == ID_c_bool)
   {
     return from_integer(
       rhs[numeric_cast_v<std::size_t>(offset)] != 0 ? 1 : 0, type);
   }
-  else if(real_type.id() == ID_pointer)
+  else if(type.id() == ID_pointer)
   {
     if(rhs[numeric_cast_v<std::size_t>(offset)] == 0)
-      return null_pointer_exprt(to_pointer_type(real_type)); // NULL pointer
+      return null_pointer_exprt(to_pointer_type(type)); // NULL pointer
 
     if(rhs[numeric_cast_v<std::size_t>(offset)] < memory.size())
     {
@@ -634,7 +632,7 @@ exprt interpretert::get_value(
 
     throw "interpreter: reading from invalid pointer";
   }
-  else if(real_type.id()==ID_string)
+  else if(type.id() == ID_string)
   {
     // Strings are currently encoded by their irep_idt ID.
     return constant_exprt(
diff --git a/src/goto-programs/interpreter_evaluate.cpp b/src/goto-programs/interpreter_evaluate.cpp
index 65570975ce9..cdb413e351e 100644
--- a/src/goto-programs/interpreter_evaluate.cpp
+++ b/src/goto-programs/interpreter_evaluate.cpp
@@ -1042,7 +1042,7 @@ mp_integer interpretert::evaluate_address(
   else if(expr.id()==ID_member)
   {
     const struct_typet &struct_type =
-      to_struct_type(ns.follow(to_member_expr(expr).compound().type()));
+      ns.follow_tag(to_struct_tag_type(to_member_expr(expr).compound().type()));
 
     const irep_idt &component_name=
       to_member_expr(expr).get_component_name();
diff --git a/src/goto-programs/json_expr.cpp b/src/goto-programs/json_expr.cpp
index 6b49f5114c3..16139131b90 100644
--- a/src/goto-programs/json_expr.cpp
+++ b/src/goto-programs/json_expr.cpp
@@ -361,24 +361,22 @@ json_objectt json(const exprt &expr, const namespacet &ns, const irep_idt &mode)
   {
     result["name"] = json_stringt("struct");
 
-    const typet &type = ns.follow(expr.type());
+    const struct_typet &struct_type =
+      expr.type().id() == ID_struct_tag
+        ? ns.follow_tag(to_struct_tag_type(expr.type()))
+        : to_struct_type(expr.type());
+    const struct_typet::componentst &components = struct_type.components();
+    DATA_INVARIANT(
+      components.size() == expr.operands().size(),
+      "number of struct components should match with its type");
 
-    // these are expected to have a struct type
-    if(type.id() == ID_struct)
+    json_arrayt &members = result["members"].make_array();
+    for(std::size_t m = 0; m < expr.operands().size(); m++)
     {
-      const struct_typet &struct_type = to_struct_type(type);
-      const struct_typet::componentst &components = struct_type.components();
-      DATA_INVARIANT(
-        components.size() == expr.operands().size(),
-        "number of struct components should match with its type");
-
-      json_arrayt &members = result["members"].make_array();
-      for(std::size_t m = 0; m < expr.operands().size(); m++)
-      {
-        json_objectt e{{"value", json(expr.operands()[m], ns, mode)},
-                       {"name", json_stringt(components[m].get_name())}};
-        members.push_back(std::move(e));
-      }
+      json_objectt e{
+        {"value", json(expr.operands()[m], ns, mode)},
+        {"name", json_stringt(components[m].get_name())}};
+      members.push_back(std::move(e));
     }
   }
   else if(expr.id() == ID_union)
diff --git a/src/goto-programs/remove_const_function_pointers.cpp b/src/goto-programs/remove_const_function_pointers.cpp
index 0ea7b54f96a..043a3107184 100644
--- a/src/goto-programs/remove_const_function_pointers.cpp
+++ b/src/goto-programs/remove_const_function_pointers.cpp
@@ -800,7 +800,8 @@ bool remove_const_function_pointerst::is_const_type(const typet &type) const
 exprt remove_const_function_pointerst::get_component_value(
   const struct_exprt &struct_expr, const member_exprt &member_expr)
 {
-  const struct_typet &struct_type=to_struct_type(ns.follow(struct_expr.type()));
+  const struct_typet &struct_type =
+    ns.follow_tag(to_struct_tag_type(struct_expr.type()));
   size_t component_number=
     struct_type.component_number(member_expr.get_component_name());
 
diff --git a/src/goto-programs/rewrite_union.cpp b/src/goto-programs/rewrite_union.cpp
index 3fcb4b33e91..71b37ed0c54 100644
--- a/src/goto-programs/rewrite_union.cpp
+++ b/src/goto-programs/rewrite_union.cpp
@@ -139,7 +139,10 @@ static bool restore_union_rec(exprt &expr, const namespacet &ns)
     byte_extract_exprt &be = to_byte_extract_expr(expr);
     if(be.op().type().id() == ID_union || be.op().type().id() == ID_union_tag)
     {
-      const union_typet &union_type = to_union_type(ns.follow(be.op().type()));
+      const union_typet &union_type =
+        be.op().type().id() == ID_union_tag
+          ? ns.follow_tag(to_union_tag_type(be.op().type()))
+          : to_union_type(be.op().type());
 
       for(const auto &comp : union_type.components())
       {
diff --git a/src/goto-programs/string_abstraction.cpp b/src/goto-programs/string_abstraction.cpp
index 5f0178c6a64..82faec7f2b0 100644
--- a/src/goto-programs/string_abstraction.cpp
+++ b/src/goto-programs/string_abstraction.cpp
@@ -353,14 +353,14 @@ exprt string_abstractiont::make_val_or_dummy_rec(goto_programt &dest,
     symbol.type.id() == ID_union_tag ||
     (symbol.type.id() == ID_struct_tag && symbol.type != string_struct))
   {
-    const struct_union_typet &su_source =
-      to_struct_union_type(ns.follow(source_type));
-    const struct_union_typet::componentst &s_components=
-      su_source.components();
-    const struct_union_typet &struct_union_type =
-      to_struct_union_type(ns.follow(symbol.type));
-    const struct_union_typet::componentst &components=
-      struct_union_type.components();
+    const struct_union_typet::componentst &s_components =
+      source_type.id() == ID_struct_tag
+        ? ns.follow_tag(to_struct_tag_type(source_type)).components()
+        : ns.follow_tag(to_union_tag_type(source_type)).components();
+    const struct_union_typet::componentst &components =
+      symbol.type.id() == ID_struct_tag
+        ? ns.follow_tag(to_struct_tag_type(symbol.type)).components()
+        : ns.follow_tag(to_union_tag_type(symbol.type)).components();
     unsigned seen=0;
 
     struct_union_typet::componentst::const_iterator it2=components.begin();
@@ -732,7 +732,10 @@ const typet &string_abstractiont::build_abstraction_type_rec(const typet &type,
   else if(type.id() == ID_struct_tag || type.id() == ID_union_tag)
   {
     const struct_union_typet &struct_union_type =
-      to_struct_union_type(ns.follow(type));
+      type.id() == ID_struct_tag ? static_cast<const struct_union_typet &>(
+                                     ns.follow_tag(to_struct_tag_type(type)))
+                                 : static_cast<const struct_union_typet &>(
+                                     ns.follow_tag(to_union_tag_type(type)));
 
     struct_union_typet::componentst new_comp;
     for(const auto &comp : struct_union_type.components())
diff --git a/src/goto-programs/xml_expr.cpp b/src/goto-programs/xml_expr.cpp
index 801149d62cb..da90516dace 100644
--- a/src/goto-programs/xml_expr.cpp
+++ b/src/goto-programs/xml_expr.cpp
@@ -253,21 +253,18 @@ xmlt xml(const exprt &expr, const namespacet &ns)
   {
     result.name = "struct";
 
-    const typet &type = ns.follow(expr.type());
+    const struct_typet &struct_type =
+      expr.type().id() == ID_struct_tag
+        ? ns.follow_tag(to_struct_tag_type(expr.type()))
+        : to_struct_type(expr.type());
+    const struct_typet::componentst &components = struct_type.components();
+    PRECONDITION(components.size() == expr.operands().size());
 
-    // these are expected to have a struct type
-    if(type.id() == ID_struct)
+    for(unsigned m = 0; m < expr.operands().size(); m++)
     {
-      const struct_typet &struct_type = to_struct_type(type);
-      const struct_typet::componentst &components = struct_type.components();
-      PRECONDITION(components.size() == expr.operands().size());
-
-      for(unsigned m = 0; m < expr.operands().size(); m++)
-      {
-        xmlt &e = result.new_element("member");
-        e.new_element() = xml(expr.operands()[m], ns);
-        e.set_attribute("name", id2string(components[m].get_name()));
-      }
+      xmlt &e = result.new_element("member");
+      e.new_element() = xml(expr.operands()[m], ns);
+      e.set_attribute("name", id2string(components[m].get_name()));
     }
   }
   else if(expr.id() == ID_union)