diff --git a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/FileSystemCounterGroup.java b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/FileSystemCounterGroup.java
index 3834d4ea88989..b94c63baacbdd 100644
--- a/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/FileSystemCounterGroup.java
+++ b/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/FileSystemCounterGroup.java
@@ -311,8 +311,11 @@ public void readFields(DataInput in) throws IOException {
       String scheme = WritableUtils.readString(in); // scheme
       int numCounters = WritableUtils.readVInt(in); // #counter
       for (int j = 0; j < numCounters; ++j) {
-        findCounter(scheme, enums[WritableUtils.readVInt(in)])  // key
+        int countTypeIndex = WritableUtils.readVInt(in);
+        if (countTypeIndex < enums.length) {
+          findCounter(scheme, enums[countTypeIndex])  // key
             .setValue(WritableUtils.readVLong(in)); // value
+        }
       }
     }
   }