diff --git a/core/src/main/java/org/elasticsearch/common/lucene/search/function/FieldValueFactorFunction.java b/core/src/main/java/org/elasticsearch/common/lucene/search/function/FieldValueFactorFunction.java
index 38c2cc98a2e..cb2babb574f 100644
--- a/core/src/main/java/org/elasticsearch/common/lucene/search/function/FieldValueFactorFunction.java
+++ b/core/src/main/java/org/elasticsearch/common/lucene/search/function/FieldValueFactorFunction.java
@@ -57,7 +57,7 @@ public class FieldValueFactorFunction extends ScoreFunction {
     public LeafScoreFunction getLeafScoreFunction(LeafReaderContext ctx) {
         final SortedNumericDoubleValues values;
         if(indexFieldData == null) {
-            values = FieldData.emptySortedNumericDoubles(0);
+            values = FieldData.emptySortedNumericDoubles(ctx.reader().maxDoc());
         } else {
             values = this.indexFieldData.load(ctx).getDoubleValues();
         }