diff --git a/src/cmp_hash.rs b/src/cmp_hash.rs
index 044d4b3..b269f12 100644
--- a/src/cmp_hash.rs
+++ b/src/cmp_hash.rs
@@ -5,7 +5,7 @@ use std::hash::{Hash, Hasher, SipHasher};
 pub fn cmp_hash<K:Hash + Eq>(x:&K, y:&K) -> Ordering{
     let mut ord = Ordering::Equal;
     let mut n = 0u64;
-    while ord.is_eq() {
+    while !x.eq(y) && ord.is_eq() {
         let mut h1 = SipHasher::new_with_keys(0, n);
         let mut h2 = SipHasher::new_with_keys(0, n);
         x.hash(&mut h1);
diff --git a/src/test_mt_map.rs b/src/test_mt_map.rs
index 1819883..f026cd0 100644
--- a/src/test_mt_map.rs
+++ b/src/test_mt_map.rs
@@ -32,6 +32,7 @@ mod tests {
     )]
     struct K {
         x:i32,
+        y:i32,
     }
 
     impl MsgTrait for K {
@@ -40,20 +41,24 @@ mod tests {
     #[test]
     fn test_mt_map_hash() {
         let mut vec = vec![];
-        for i in 0..20 {
-            let k = K {
-                x:i
-            };
-            let v = K {
-                x:i + 1
-            };
-            vec.push((k, v));
+        for j in 0..10 {
+            for i in 0..20 {
+                let k = K {
+                    x: i,
+                    y:j
+                };
+                let v = K {
+                    x: i + 1,
+                    y:j + 1
+                };
+                vec.push((k, v));
+            }
+            let map1 = MTMap::from_vec(vec.clone());
+            let map2 = MTMap::from_vec(vec.clone());
+            assert_eq!(map1, map2);
+            let mut hash_set = HashSet::new();
+            hash_set.insert(map1);
+            assert!(hash_set.contains(&map2));
         }
-        let map1 = MTMap::from_vec(vec.clone());
-        let map2 =  MTMap::from_vec(vec.clone());
-        assert_eq!(map1, map2);
-        let mut hash_set = HashSet::new();
-        hash_set.insert(map1);
-        assert!(hash_set.contains(&map2));
     }
 }
\ No newline at end of file
diff --git a/src/test_mt_set.rs b/src/test_mt_set.rs
index 7fe3cbb..832fb65 100644
--- a/src/test_mt_set.rs
+++ b/src/test_mt_set.rs
@@ -30,6 +30,7 @@ mod tests {
     )]
     struct V {
         x : i32,
+        y: i32,
     }
 
     impl MsgTrait for V {
@@ -38,17 +39,21 @@ mod tests {
     #[test]
     fn test_mt_set_hash() {
         let mut vec = vec![];
-        for i in 0..20 {
-            let v = V {
-                x:i
-            };
-            vec.push(v);
+        for j in 0..10 {
+            for i in 0..20 {
+                let v = V {
+                    x: i,
+                    y: j
+                };
+                vec.push(v);
+            }
+            let set1 = MTSet::from_vec(vec.clone());
+            let set2 = MTSet::from_vec(vec.clone());
+            assert_eq!(set1, set2);
+            let mut hash_set = HashSet::new();
+            hash_set.insert(set1);
+            assert!(!hash_set.insert(set2.clone()));
+            assert!(hash_set.contains(&set2));
         }
-        let set1 = MTSet::from_vec(vec.clone());
-        let set2 = MTSet::from_vec(vec.clone());
-        assert_eq!(set1, set2);
-        let mut hash_set = HashSet::new();
-        hash_set.insert(set1);
-        assert!(hash_set.contains(&set2));
     }
 }
\ No newline at end of file