--- src/check.cpp.orig	2019-09-09 09:09:42.511584867 -0600
+++ src/check.cpp	2019-09-09 09:10:28.396752570 -0600
@@ -33,7 +33,7 @@ std::vector<Expr *> ascHoles;
 
 Trie<pair<Expr *, Expr *> > *symbols = new Trie<pair<Expr *, Expr *> >;
 
-hash_map<string, bool> imports;
+std::unordered_map<string, bool> imports;
 std::map<SymExpr *, int> mark_map;
 std::vector<std::pair<std::string, std::pair<Expr *, Expr *> > >
     local_sym_names;
--- src/check.h.orig	2019-08-08 13:50:19.000000000 -0600
+++ src/check.h	2019-09-09 09:09:42.511584867 -0600
@@ -8,7 +8,7 @@
 #include <stdio.h>
 #include <hash_map>
 #else
-#include <ext/hash_map>
+#include <unordered_map>
 #endif
 
 #include <cstddef>
@@ -158,8 +158,8 @@ inline const char *prefix_id(bool skip_w
 typedef std::hash_map<std::string, Expr *> symmap;
 typedef std::hash_map<std::string, SymExpr *> symmap2;
 #else
-typedef __gnu_cxx::hash_map<std::string, Expr *> symmap;
-typedef __gnu_cxx::hash_map<std::string, SymExpr *> symmap2;
+typedef std::unordered_map<std::string, Expr *> symmap;
+typedef std::unordered_map<std::string, SymExpr *> symmap2;
 #endif
 extern symmap2 progs;
 extern std::vector<Expr *> ascHoles;
@@ -171,19 +171,6 @@ extern std::map<SymExpr *, int> mark_map
 extern std::vector<std::pair<std::string, std::pair<Expr *, Expr *> > >
     local_sym_names;
 
-#ifndef _MSC_VER
-namespace __gnu_cxx {
-template <>
-struct hash<std::string>
-{
-  size_t operator()(const std::string &x) const
-  {
-    return hash<const char *>()(x.c_str());
-  }
-};
-}  // namespace __gnu_cxx
-#endif
-
 extern Expr *statMpz;
 extern Expr *statMpq;
 extern Expr *statType;