diff --git a/src/test/uint_set.cpp b/src/test/uint_set.cpp
index 582a1d42f..fcbbd5c48 100644
--- a/src/test/uint_set.cpp
+++ b/src/test/uint_set.cpp
@@ -131,6 +131,32 @@ static void tst4() {
     SASSERT(!s.contains(0));
 }
 
+#include "map.h"
+
+template <typename Value>
+struct uint_map : public map<uint_set, Value, uint_set::hash, uint_set::eq> {};
+
+static void tst5() {
+    uint_set s;
+    std::cout << s.get_hash() << "\n";
+    s.insert(1);
+    std::cout << s.get_hash() << "\n";
+    s.insert(2);
+    std::cout << s.get_hash() << "\n";
+    s.insert(44);
+    std::cout << s.get_hash() << "\n";
+
+    uint_map<unsigned> m;
+    m.insert(s, 1);
+    s.insert(4);
+    m.insert(s, 3);
+    uint_map<unsigned>::iterator it = m.begin(), end = m.end();
+    for (; it != end; ++it) {
+        std::cout << it->m_key << " : " << it->m_value << "\n";
+    }
+    
+}
+
 void tst_uint_set() {
     for (unsigned i = 0; i < 100; i++) {
         tst1(1 + rand()%31);
@@ -146,5 +172,6 @@ void tst_uint_set() {
     tst3(12);
     tst3(100);
     tst4();
+    tst5();
 }
 
diff --git a/src/util/uint_set.h b/src/util/uint_set.h
index aca73a5c5..525638f4f 100644
--- a/src/util/uint_set.h
+++ b/src/util/uint_set.h
@@ -218,6 +218,18 @@ public:
 
     iterator const begin() const { return iterator(*this, false); }
     iterator const end() const { return iterator(*this, true); }
+
+    unsigned get_hash() const {
+        unsigned h = 0;
+        for (unsigned i = 0; i < size(); ++i) {
+            h += (i+1)*((*this)[i]);
+        }
+        return h;
+    }
+
+    struct eq { bool operator()(uint_set const& s1, uint_set const& s2) const { return s1 == s2; } };
+    struct hash { unsigned operator()(uint_set const& s) const { return s.get_hash(); } };
+        
 };
 
 inline std::ostream & operator<<(std::ostream & target, const uint_set & s) {