diff --git a/src/goto-programs/link_goto_model.cpp b/src/goto-programs/link_goto_model.cpp
index 8dd0d87edf6..716f9816dd7 100644
--- a/src/goto-programs/link_goto_model.cpp
+++ b/src/goto-programs/link_goto_model.cpp
@@ -118,13 +118,12 @@ static bool link_functions(
       const irep_idt &id = to_symbol_expr(symbol.value).get_identifier();
 
       #if 0
-      if(!base_type_eq(symbol.type, ns.lookup(id).type, ns))
+      if(symbol.type != ns.lookup(id).type)
       {
         std::cerr << symbol << '\n';
         std::cerr << ns.lookup(id) << '\n';
       }
-      INVARIANT(base_type_eq(symbol.type, ns.lookup(id).type, ns),
-                "type matches");
+      INVARIANT(symbol.type == ns.lookup(id).type, "type matches");
       #endif
 
       macro_application.insert_expr(symbol.name, id);
diff --git a/src/goto-programs/string_abstraction.cpp b/src/goto-programs/string_abstraction.cpp
index 2ac290e1f4c..2478ad785fa 100644
--- a/src/goto-programs/string_abstraction.cpp
+++ b/src/goto-programs/string_abstraction.cpp
@@ -35,9 +35,9 @@ bool string_abstractiont::build_wrap(
   // #define build_wrap(a,b,c) build(a,b,c)
   // to avoid it
   const typet &a_t=build_abstraction_type(object.type());
-  /*assert(type_eq(dest.type(), a_t, ns) ||
+  /*assert(dest.type() == a_t ||
       (dest.type().id()==ID_array && a_t.id()==ID_pointer &&
-       type_eq(dest.type().subtype(), a_t.subtype(), ns)));
+       dest.type().subtype() == a_t.subtype()));
        */
   if(
     dest.type() != a_t &&
diff --git a/src/pointer-analysis/value_set.cpp b/src/pointer-analysis/value_set.cpp
index e1d4fe34d10..8f5abba8f16 100644
--- a/src/pointer-analysis/value_set.cpp
+++ b/src/pointer-analysis/value_set.cpp
@@ -1156,10 +1156,10 @@ void value_sett::assign(
       }
       else
       {
-        if(rhs.type() != type)
+        if(rhs.type() != lhs.type())
           throw "value_sett::assign type mismatch: "
                 "rhs.type():\n"+rhs.type().pretty()+"\n"+
-                "type:\n"+type.pretty();
+                "lhs.type():\n"+lhs.type().pretty();
 
         rhs_member=make_member(rhs, name, ns);
 
diff --git a/src/solvers/flattening/boolbv_equality.cpp b/src/solvers/flattening/boolbv_equality.cpp
index 8d47275b7d8..1be84441cf2 100644
--- a/src/solvers/flattening/boolbv_equality.cpp
+++ b/src/solvers/flattening/boolbv_equality.cpp
@@ -17,9 +17,9 @@ Author: Daniel Kroening, kroening@kroening.com
 
 literalt boolbvt::convert_equality(const equal_exprt &expr)
 {
-  const bool is_base_type_eq = expr.lhs().type() == expr.rhs().type();
+  const bool equality_types_match = expr.lhs().type() == expr.rhs().type();
   DATA_INVARIANT_WITH_DIAGNOSTICS(
-    is_base_type_eq,
+    equality_types_match,
     "types of expressions on each side of equality should match",
     irep_pretty_diagnosticst{expr.lhs()},
     irep_pretty_diagnosticst{expr.rhs()});
diff --git a/src/util/simplify_expr_struct.cpp b/src/util/simplify_expr_struct.cpp
index 748d7c33958..3a525267371 100644
--- a/src/util/simplify_expr_struct.cpp
+++ b/src/util/simplify_expr_struct.cpp
@@ -262,9 +262,6 @@ bool simplify_exprt::simplify_member(exprt &expr)
 
         // Guess: turning this into a byte-extract operation is not really an
         // optimisation.
-        // The type_eq check is because get_subexpression_at_offset uses
-        // base_type_eq, whereas in the context of a simplifier we should not
-        // change the type of the expression.
         if(
           equivalent_member.is_not_nil() &&
           equivalent_member.id() != ID_byte_extract_little_endian &&