update this.map  to values
diff --git a/cache/src/main/java/org/apache/shiro/cache/MapCache.java b/cache/src/main/java/org/apache/shiro/cache/MapCache.java
index 024f5ef..06dfde9 100644
--- a/cache/src/main/java/org/apache/shiro/cache/MapCache.java
+++ b/cache/src/main/java/org/apache/shiro/cache/MapCache.java
@@ -82,10 +82,10 @@
 
     public Collection<V> values() {
         Collection<V> values = map.values();
-        if (!map.isEmpty()) {
+        if (!values.isEmpty()) {
             return Collections.unmodifiableCollection(values);
         }
-        return Collections.emptySet();
+        return Collections.emptyList();
     }
 
     public String toString() {