diff --git a/CHANGES.txt b/CHANGES.txt
index f41af9fc33d..21236c4ad73 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -108,6 +108,7 @@ Release 0.90.1 - Unreleased
   
   BUG FIXES
    HBASE-3483  Memstore lower limit should trigger asynchronous flushes
+   HBASE-3524  NPE from CompactionChecker
 
   IMPROVEMENTS
    HBASE-3508  LruBlockCache statistics thread should have a name
diff --git a/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java b/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
index 47cf8e728a5..a7e2720f9e9 100644
--- a/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
+++ b/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java
@@ -788,7 +788,10 @@ public class Store implements HeapSize {
       if (filesToCompact.size() == 1) {
         // Single file
         StoreFile sf = filesToCompact.get(0);
-        long oldest = now - sf.getReader().timeRangeTracker.minimumTimestamp;
+        long oldest =
+            (sf.getReader().timeRangeTracker == null) ?
+                Long.MIN_VALUE :
+                now - sf.getReader().timeRangeTracker.minimumTimestamp;
         if (sf.isMajorCompaction() &&
             (this.ttl == HConstants.FOREVER || oldest < this.ttl)) {
           if (LOG.isDebugEnabled()) {