diff --git a/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/lucene/LuceneIndex.java b/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/lucene/LuceneIndex.java
index 15828e8..992cdb5 100644
--- a/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/lucene/LuceneIndex.java
+++ b/oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/lucene/LuceneIndex.java
@@ -165,11 +165,13 @@ public class LuceneIndex implements QueryIndex {
                 last = pr.last.getString();
             }
 
-            if (first.equals(last) && pr.firstIncluding && pr.lastIncluding) {
-                qs.add(new TermQuery(new Term(name, first)));
-            } else {
-                qs.add(TermRangeQuery.newStringRange(name, first, last,
-                        pr.firstIncluding, pr.lastIncluding));
+            if (first != null) {
+                if (first.equals(last) && pr.firstIncluding && pr.lastIncluding) {
+                    qs.add(new TermQuery(new Term(name, first)));
+                } else {
+                    qs.add(TermRangeQuery.newStringRange(name, first, last,
+                            pr.firstIncluding, pr.lastIncluding));
+                }
             }
         }