diff --git a/src/main/java/org/apache/commons/collections4/map/MultiKeyMap.java b/src/main/java/org/apache/commons/collections4/map/MultiKeyMap.java
index 71e468f6fe..19cd48def4 100644
--- a/src/main/java/org/apache/commons/collections4/map/MultiKeyMap.java
+++ b/src/main/java/org/apache/commons/collections4/map/MultiKeyMap.java
@@ -162,7 +162,7 @@ public MultiKeyMap<K, V> clone() {
      * @param key2  the second key
      * @return true if the map contains the key
      */
-    public boolean containsKey(final Object key1, final Object key2) {
+    public boolean containsKey(final K key1, final K key2) {
         final int hashCode = hash(key1, key2);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -182,7 +182,7 @@ public boolean containsKey(final Object key1, final Object key2) {
      * @param key3  the third key
      * @return true if the map contains the key
      */
-    public boolean containsKey(final Object key1, final Object key2, final Object key3) {
+    public boolean containsKey(final K key1, final K key2, final K key3) {
         final int hashCode = hash(key1, key2, key3);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -203,7 +203,7 @@ public boolean containsKey(final Object key1, final Object key2, final Object ke
      * @param key4  the fourth key
      * @return true if the map contains the key
      */
-    public boolean containsKey(final Object key1, final Object key2, final Object key3, final Object key4) {
+    public boolean containsKey(final K key1, final K key2, final K key3, final K key4) {
         final int hashCode = hash(key1, key2, key3, key4);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -225,7 +225,7 @@ public boolean containsKey(final Object key1, final Object key2, final Object ke
      * @param key5  the fifth key
      * @return true if the map contains the key
      */
-    public boolean containsKey(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) {
+    public boolean containsKey(final K key1, final K key2, final K key3, final K key4, final K key5) {
         final int hashCode = hash(key1, key2, key3, key4, key5);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -260,7 +260,7 @@ int decoratedHashIndex(final int hashCode) {
      * @param key2  the second key
      * @return the mapped value, null if no match
      */
-    public V get(final Object key1, final Object key2) {
+    public V get(final K key1, final K key2) {
         final int hashCode = hash(key1, key2);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -280,7 +280,7 @@ public V get(final Object key1, final Object key2) {
      * @param key3  the third key
      * @return the mapped value, null if no match
      */
-    public V get(final Object key1, final Object key2, final Object key3) {
+    public V get(final K key1, final K key2, final K key3) {
         final int hashCode = hash(key1, key2, key3);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -301,7 +301,7 @@ public V get(final Object key1, final Object key2, final Object key3) {
      * @param key4  the fourth key
      * @return the mapped value, null if no match
      */
-    public V get(final Object key1, final Object key2, final Object key3, final Object key4) {
+    public V get(final K key1, final K key2, final K key3, final K key4) {
         final int hashCode = hash(key1, key2, key3, key4);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -323,7 +323,7 @@ public V get(final Object key1, final Object key2, final Object key3, final Obje
      * @param key5  the fifth key
      * @return the mapped value, null if no match
      */
-    public V get(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) {
+    public V get(final K key1, final K key2, final K key3, final K key4, final K key5) {
         final int hashCode = hash(key1, key2, key3, key4, key5);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decoratedHashEntry(hashCode);
         while (entry != null) {
@@ -342,7 +342,7 @@ public V get(final Object key1, final Object key2, final Object key3, final Obje
      * @param key2  the second key
      * @return the hash code
      */
-    protected int hash(final Object key1, final Object key2) {
+    protected int hash(final K key1, final K key2) {
         int h = 0;
         if (key1 != null) {
             h ^= key1.hashCode();
@@ -365,7 +365,7 @@ protected int hash(final Object key1, final Object key2) {
      * @param key3  the third key
      * @return the hash code
      */
-    protected int hash(final Object key1, final Object key2, final Object key3) {
+    protected int hash(final K key1, final K key2, final K key3) {
         int h = 0;
         if (key1 != null) {
             h ^= key1.hashCode();
@@ -392,7 +392,7 @@ protected int hash(final Object key1, final Object key2, final Object key3) {
      * @param key4  the fourth key
      * @return the hash code
      */
-    protected int hash(final Object key1, final Object key2, final Object key3, final Object key4) {
+    protected int hash(final K key1, final K key2, final K key3, final K key4) {
         int h = 0;
         if (key1 != null) {
             h ^= key1.hashCode();
@@ -423,7 +423,7 @@ protected int hash(final Object key1, final Object key2, final Object key3, fina
      * @param key5  the fifth key
      * @return the hash code
      */
-    protected int hash(final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) {
+    protected int hash(final K key1, final K key2, final K key3, final K key4, final K key5) {
         int h = 0;
         if (key1 != null) {
             h ^= key1.hashCode();
@@ -456,7 +456,7 @@ protected int hash(final Object key1, final Object key2, final Object key3, fina
      * @return true if the key matches
      */
     protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry,
-            final Object key1, final Object key2) {
+            final K key1, final K key2) {
         final MultiKey<? extends K> multi = entry.getKey();
         return
             multi.size() == 2 &&
@@ -474,7 +474,7 @@ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extend
      * @return true if the key matches
      */
     protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry,
-                                 final Object key1, final Object key2, final Object key3) {
+                                 final K key1, final K key2, final K key3) {
         final MultiKey<? extends K> multi = entry.getKey();
         return
             multi.size() == 3 &&
@@ -494,7 +494,7 @@ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extend
      * @return true if the key matches
      */
     protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry,
-                                 final Object key1, final Object key2, final Object key3, final Object key4) {
+                                 final K key1, final K key2, final K key3, final K key4) {
         final MultiKey<? extends K> multi = entry.getKey();
         return
             multi.size() == 4 &&
@@ -516,7 +516,7 @@ protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extend
      * @return true if the key matches
      */
     protected boolean isEqualKey(final AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry,
-            final Object key1, final Object key2, final Object key3, final Object key4, final Object key5) {
+            final K key1, final K key2, final K key3, final K key4, final K key5) {
         final MultiKey<? extends K> multi = entry.getKey();
         return
             multi.size() == 5 &&
@@ -689,7 +689,7 @@ private void readObject(final ObjectInputStream in) throws IOException, ClassNot
      * @param key1  the first key
      * @return true if any elements were removed
      */
-    public boolean removeAll(final Object key1) {
+    public boolean removeAll(final K key1) {
         boolean modified = false;
         final MapIterator<MultiKey<? extends K>, V> it = mapIterator();
         while (it.hasNext()) {
@@ -714,7 +714,7 @@ public boolean removeAll(final Object key1) {
      * @param key2  the second key
      * @return true if any elements were removed
      */
-    public boolean removeAll(final Object key1, final Object key2) {
+    public boolean removeAll(final K key1, final K key2) {
         boolean modified = false;
         final MapIterator<MultiKey<? extends K>, V> it = mapIterator();
         while (it.hasNext()) {
@@ -741,7 +741,7 @@ public boolean removeAll(final Object key1, final Object key2) {
      * @param key3  the third key
      * @return true if any elements were removed
      */
-    public boolean removeAll(final Object key1, final Object key2, final Object key3) {
+    public boolean removeAll(final K key1, final K key2, final K key3) {
         boolean modified = false;
         final MapIterator<MultiKey<? extends K>, V> it = mapIterator();
         while (it.hasNext()) {
@@ -770,7 +770,7 @@ public boolean removeAll(final Object key1, final Object key2, final Object key3
      * @param key4  the fourth key
      * @return true if any elements were removed
      */
-    public boolean removeAll(final Object key1, final Object key2, final Object key3, final Object key4) {
+    public boolean removeAll(final K key1, final K key2, final K key3, final K key4) {
         boolean modified = false;
         final MapIterator<MultiKey<? extends K>, V> it = mapIterator();
         while (it.hasNext()) {
@@ -793,9 +793,9 @@ public boolean removeAll(final Object key1, final Object key2, final Object key3
      * @param key1  the first key
      * @param key2  the second key
      * @return the value mapped to the removed key, null if key not in map
-     * @since 4.0 (previous name: remove(Object, Object))
+     * @since 4.0 (previous name: remove(K, K))
      */
-    public V removeMultiKey(final Object key1, final Object key2) {
+    public V removeMultiKey(final K key1, final K key2) {
         final int hashCode = hash(key1, key2);
         final int index = decoratedHashIndex(hashCode);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index];
@@ -819,9 +819,9 @@ public V removeMultiKey(final Object key1, final Object key2) {
      * @param key2  the second key
      * @param key3  the third key
      * @return the value mapped to the removed key, null if key not in map
-     * @since 4.0 (previous name: remove(Object, Object, Object))
+     * @since 4.0 (previous name: remove(K, K, K))
      */
-    public V removeMultiKey(final Object key1, final Object key2, final Object key3) {
+    public V removeMultiKey(final K key1, final K key2, final K key3) {
         final int hashCode = hash(key1, key2, key3);
         final int index = decoratedHashIndex(hashCode);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index];
@@ -846,9 +846,9 @@ public V removeMultiKey(final Object key1, final Object key2, final Object key3)
      * @param key3  the third key
      * @param key4  the fourth key
      * @return the value mapped to the removed key, null if key not in map
-     * @since 4.0 (previous name: remove(Object, Object, Object, Object))
+     * @since 4.0 (previous name: remove(K, K, K, K))
      */
-    public V removeMultiKey(final Object key1, final Object key2, final Object key3, final Object key4) {
+    public V removeMultiKey(final K key1, final K key2, final K key3, final K key4) {
         final int hashCode = hash(key1, key2, key3, key4);
         final int index = decoratedHashIndex(hashCode);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index];
@@ -874,10 +874,10 @@ public V removeMultiKey(final Object key1, final Object key2, final Object key3,
      * @param key4  the fourth key
      * @param key5  the fifth key
      * @return the value mapped to the removed key, null if key not in map
-     * @since 4.0 (previous name: remove(Object, Object, Object, Object, Object))
+     * @since 4.0 (previous name: remove(K, K, K, K, K))
      */
-    public V removeMultiKey(final Object key1, final Object key2, final Object key3,
-                            final Object key4, final Object key5) {
+    public V removeMultiKey(final K key1, final K key2, final K key3,
+                            final K key4, final K key5) {
         final int hashCode = hash(key1, key2, key3, key4, key5);
         final int index = decoratedHashIndex(hashCode);
         AbstractHashedMap.HashEntry<MultiKey<? extends K>, V> entry = decorated().data[index];
diff --git a/src/test/java/org/apache/commons/collections4/map/MultiKeyMapTest.java b/src/test/java/org/apache/commons/collections4/map/MultiKeyMapTest.java
index 456269a275..34d9d0cd61 100644
--- a/src/test/java/org/apache/commons/collections4/map/MultiKeyMapTest.java
+++ b/src/test/java/org/apache/commons/collections4/map/MultiKeyMapTest.java
@@ -172,19 +172,19 @@ public void testLRUMultiKeyMap() {
         assertEquals(2, map.size());
         map.put((K) I1, (K) I4, (V) "1-4");
         assertEquals(2, map.size());
-        assertTrue(map.containsKey(I1, I3));
-        assertTrue(map.containsKey(I1, I4));
-        assertFalse(map.containsKey(I1, I2));
+        assertTrue(map.containsKey((K) I1,(K) I3));
+        assertTrue(map.containsKey((K) I1,(K) I4));
+        assertFalse(map.containsKey((K) I1, (K) I2));
 
         final MultiKeyMap<K, V> cloned = map.clone();
         assertEquals(2, map.size());
-        assertTrue(cloned.containsKey(I1, I3));
-        assertTrue(cloned.containsKey(I1, I4));
-        assertFalse(cloned.containsKey(I1, I2));
+        assertTrue(cloned.containsKey((K) I1, (K) I3));
+        assertTrue(cloned.containsKey((K) I1, (K) I4));
+        assertFalse(cloned.containsKey((K) I1, (K) I2));
         cloned.put((K) I1, (K) I5, (V) "1-5");
         assertEquals(2, cloned.size());
-        assertTrue(cloned.containsKey(I1, I4));
-        assertTrue(cloned.containsKey(I1, I5));
+        assertTrue(cloned.containsKey((K) I1, (K) I4));
+        assertTrue(cloned.containsKey((K) I1, (K) I5));
     }
 
     @Test
@@ -428,7 +428,7 @@ public void testMultiKeyRemoveAll1() {
         final MultiKeyMap<K, V> multimap = getMap();
         assertEquals(12, multimap.size());
 
-        multimap.removeAll(I1);
+        multimap.removeAll((K) I1);
         assertEquals(8, multimap.size());
         for (final MapIterator<MultiKey<? extends K>, V> it = multimap.mapIterator(); it.hasNext();) {
             final MultiKey<? extends K> key = it.next();
@@ -442,7 +442,7 @@ public void testMultiKeyRemoveAll2() {
         final MultiKeyMap<K, V> multimap = getMap();
         assertEquals(12, multimap.size());
 
-        multimap.removeAll(I2, I3);
+        multimap.removeAll((K) I2, (K) I3);
         assertEquals(9, multimap.size());
         for (final MapIterator<MultiKey<? extends K>, V> it = multimap.mapIterator(); it.hasNext();) {
             final MultiKey<? extends K> key = it.next();
@@ -456,7 +456,7 @@ public void testMultiKeyRemoveAll3() {
         final MultiKeyMap<K, V> multimap = getMap();
         assertEquals(12, multimap.size());
 
-        multimap.removeAll(I1, I1, I2);
+        multimap.removeAll((K) I1, (K) I1, (K) I2);
         assertEquals(9, multimap.size());
         for (final MapIterator<MultiKey<? extends K>, V> it = multimap.mapIterator(); it.hasNext();) {
             final MultiKey<? extends K> key = it.next();
@@ -481,7 +481,7 @@ public void testMultiKeyRemoveAll4() {
         final MultiKeyMap<K, V> multimap = getMap();
         assertEquals(12, multimap.size());
 
-        multimap.removeAll(I1, I1, I2, I3);
+        multimap.removeAll((K) I1, (K) I1, (K) I2, (K) I3);
         assertEquals(10, multimap.size());
         for (final MapIterator<MultiKey<? extends K>, V> it = multimap.mapIterator(); it.hasNext();) {
             final MultiKey<? extends K> key = it.next();