diff --git a/common/common-lang/src/main/java/com/twelvemonkeys/util/AbstractDecoratedMap.java b/common/common-lang/src/main/java/com/twelvemonkeys/util/AbstractDecoratedMap.java
index a354be08..bb144842 100755
--- a/common/common-lang/src/main/java/com/twelvemonkeys/util/AbstractDecoratedMap.java
+++ b/common/common-lang/src/main/java/com/twelvemonkeys/util/AbstractDecoratedMap.java
@@ -330,7 +330,7 @@ abstract class AbstractDecoratedMap<K, V> extends AbstractMap<K, V> implements M
     }
 
     /**
-     * A simple Map.Entry implementaton.
+     * A simple Map.Entry implementation.
      */
     static class BasicEntry<K, V> implements Entry<K, V>, Serializable {
         K mKey;
diff --git a/common/common-lang/src/main/java/com/twelvemonkeys/util/TimeoutMap.java b/common/common-lang/src/main/java/com/twelvemonkeys/util/TimeoutMap.java
index b3199f56..50dd8839 100755
--- a/common/common-lang/src/main/java/com/twelvemonkeys/util/TimeoutMap.java
+++ b/common/common-lang/src/main/java/com/twelvemonkeys/util/TimeoutMap.java
@@ -34,7 +34,7 @@ import java.io.Serializable;
 import java.util.*;
 
 /**
- * A {@code Map} implementation that removes (exipres) its elements after
+ * A {@code Map} implementation that removes (expires) its elements after
  * a given period. The map is by default backed by a {@link java.util.HashMap},
  * or can be instantiated with any given {@code Map} as backing.
  * <p>
@@ -67,7 +67,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
     protected long expiryTime = 60000L;  // 1 minute
 
     //////////////////////
-    private volatile long nextExpiryTime;
+    private volatile long nextExpiryTime = Long.MAX_VALUE;
     //////////////////////
 
     /**
@@ -178,7 +178,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
      * @return {@code true} if this map contains no key-value mappings.
      */
     public boolean isEmpty() {
-        return (size() <= 0);
+        return size() <= 0;
     }
 
     /**
@@ -208,7 +208,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
      * @see #containsKey(java.lang.Object)
      */
     public V get(Object pKey) {
-        TimedEntry<K, V> entry = (TimedEntry<K, V>) entries.get(pKey);
+        TimedEntry entry = (TimedEntry) entries.get(pKey);
 
         if (entry == null) {
             return null;
@@ -236,7 +236,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
      *         {@code null} values.
      */
     public V put(K pKey, V pValue) {
-        TimedEntry<K, V> entry = (TimedEntry<K, V>) entries.get(pKey);
+        TimedEntry entry = (TimedEntry) entries.get(pKey);
         V oldValue;
 
         if (entry == null) {
@@ -272,7 +272,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
      *         {@code null} values.
      */
     public V remove(Object pKey) {
-        TimedEntry<K, V> entry = (TimedEntry<K, V>) entries.remove(pKey);
+        TimedEntry entry = (TimedEntry) entries.remove(pKey);
         return (entry != null) ? entry.getValue() : null;
     }
 
@@ -284,13 +284,12 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
         init();
     }
 
-    /*protected*/ TimedEntry<K, V> createEntry(K pKey, V pValue) {
-        return new TimedEntry<K, V>(pKey, pValue);
+    /*protected*/ TimedEntry createEntry(K pKey, V pValue) {
+        return new TimedEntry(pKey, pValue);
     }
 
     /**
      * Removes any expired mappings.
-     *
      */
     protected void removeExpiredEntries() {
         // Remove any expired elements
@@ -312,7 +311,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
             long next = Long.MAX_VALUE;
             nextExpiryTime = next; // Avoid multiple runs...
             for (Iterator<Entry<K, V>> iterator = new EntryIterator(); iterator.hasNext();) {
-                TimedEntry<K, V> entry = (TimedEntry<K, V>) iterator.next();
+                TimedEntry entry = (TimedEntry) iterator.next();
                 ////
                 long expires = entry.expires();
                 if (expires < next) {
@@ -376,7 +375,7 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
 
             while (mNext == null && mIterator.hasNext()) {
                 Entry<K, Entry<K, V>> entry = mIterator.next();
-                TimedEntry<K, V> timed = (TimedEntry<K, V>) entry.getValue();
+                TimedEntry timed = (TimedEntry) entry.getValue();
 
                 if (timed.isExpiredBy(mNow)) {
                     // Remove from map, and continue
@@ -425,19 +424,28 @@ public class TimeoutMap<K, V> extends AbstractDecoratedMap<K, V> implements Expi
     /**
      * Keeps track of timed objects
      */
-    private class TimedEntry<K, V> extends BasicEntry<K, V> {
+    private class TimedEntry extends BasicEntry<K, V> {
         private long mTimestamp;
 
         TimedEntry(K pKey, V pValue) {
             super(pKey, pValue);
-            mTimestamp = System.currentTimeMillis();
+            updateTimestamp();
         }
 
         public V setValue(V pValue) {
-            mTimestamp = System.currentTimeMillis();
+            updateTimestamp();
             return super.setValue(pValue);
         }
 
+        private void updateTimestamp() {
+            mTimestamp = System.currentTimeMillis();
+
+            long expires = expires();
+            if (expires < nextExpiryTime) {
+                nextExpiryTime = expires;
+            }
+        }
+
         final boolean isExpired() {
             return isExpiredBy(System.currentTimeMillis());
         }
diff --git a/common/common-lang/src/test/java/com/twelvemonkeys/util/TimeoutMapTest.java b/common/common-lang/src/test/java/com/twelvemonkeys/util/TimeoutMapTest.java
index 1ca479b5..dfd297e0 100755
--- a/common/common-lang/src/test/java/com/twelvemonkeys/util/TimeoutMapTest.java
+++ b/common/common-lang/src/test/java/com/twelvemonkeys/util/TimeoutMapTest.java
@@ -557,7 +557,7 @@ public class TimeoutMapTest extends MapAbstractTest {
                 // NOTE: Only wait fist time, to avoid slooow tests
                 synchronized (this) {
                     try {
-                        wait(60l);
+                        wait(60L);
                     }
                     catch (InterruptedException e) {
                     }
@@ -591,7 +591,7 @@ public class TimeoutMapTest extends MapAbstractTest {
                     try {
                         wait(60l);
                     }
-                    catch (InterruptedException e) {
+                    catch (InterruptedException ignore) {
                     }
                 }
             }
@@ -651,5 +651,24 @@ public class TimeoutMapTest extends MapAbstractTest {
         assertTrue("Wrong entry removed, keySet().iterator() is broken.", !map.containsKey(removedKey));
         assertTrue("Wrong entry removed, keySet().iterator() is broken.", map.containsKey(otherKey));
     }
+
+
+    @Test
+    public void testContainsKeyOnEmptyMap() {
+        // See #600
+        Map<String, String> timeoutMap = new TimeoutMap<>(30);
+        assertFalse(timeoutMap.containsKey("xyz"));
+        timeoutMap.put("xyz", "xyz");
+        assertTrue(timeoutMap.containsKey("xyz"));
+
+        try {
+            Thread.sleep(50); // Let the item expire
+        }
+        catch (InterruptedException ignore) {
+        }
+
+        assertFalse(timeoutMap.containsKey("xyz"));
+        assertNull(timeoutMap.get("xyz"));
+    }
 }