diff --git a/library/src/com/nostra13/universalimageloader/cache/memory/BaseMemoryCache.java b/library/src/com/nostra13/universalimageloader/cache/memory/BaseMemoryCache.java
index 191533327..04d14e2a1 100644
--- a/library/src/com/nostra13/universalimageloader/cache/memory/BaseMemoryCache.java
+++ b/library/src/com/nostra13/universalimageloader/cache/memory/BaseMemoryCache.java
@@ -57,7 +57,9 @@ public void remove(K key) {
 
 	@Override
 	public Collection<K> keys() {
-		return new HashSet<K>(softMap.keySet());
+		synchronized (softMap) {
+			return new HashSet<K>(softMap.keySet());
+		}
 	}
 
 	@Override