diff --git a/processing/src/main/java/io/druid/segment/IndexMerger.java b/processing/src/main/java/io/druid/segment/IndexMerger.java
index 77063e5104e..1831e1a1f67 100644
--- a/processing/src/main/java/io/druid/segment/IndexMerger.java
+++ b/processing/src/main/java/io/druid/segment/IndexMerger.java
@@ -946,9 +946,6 @@ public class IndexMerger
           }
 
           MutableBitmap bitset = bitmapSerdeFactory.getBitmapFactory().makeEmptyMutableBitmap();
-          if ((dictId == 0) && (Iterables.getFirst(dimVals, "") == null)) {
-            bitset.or(nullRowsList.get(i));
-          }
           for (Integer row : CombiningIterable.createSplatted(
               convertedInverteds,
               Ordering.<Integer>natural().nullsFirst()
@@ -958,6 +955,10 @@ public class IndexMerger
             }
           }
 
+          if ((dictId == 0) && (Iterables.getFirst(dimVals, "") == null)) {
+            bitset.or(nullRowsList.get(i));
+          }
+
           writer.write(
               bitmapSerdeFactory.getBitmapFactory().makeImmutableBitmap(bitset)
           );