diff --git a/CHANGES.txt b/CHANGES.txt
index c4247c0ade1..c8eff2ed87c 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -449,6 +449,9 @@ Bug Fixes
     SolrQueryParser considers special.
     (hossman)
 
+54. SOLR-1317: Fix CapitalizationFilterFactory to work when keep parameter is not specified.
+    (ehatcher)
+
 Other Changes
 ----------------------
  1. Upgraded to Lucene 2.4.0 (yonik)
diff --git a/src/java/org/apache/solr/analysis/CapitalizationFilterFactory.java b/src/java/org/apache/solr/analysis/CapitalizationFilterFactory.java
index db6377f923c..96dcf46df71 100644
--- a/src/java/org/apache/solr/analysis/CapitalizationFilterFactory.java
+++ b/src/java/org/apache/solr/analysis/CapitalizationFilterFactory.java
@@ -141,7 +141,7 @@ public class CapitalizationFilterFactory extends BaseTokenFilterFactory {
       return;
     }
 
-    if (keep.contains(buffer, offset, length)) {
+    if (keep != null && keep.contains(buffer, offset, length)) {
       if (wordCount == 0 && forceFirstLetter) {
         buffer[offset] = Character.toUpperCase(buffer[offset]);
       }
diff --git a/src/test/org/apache/solr/analysis/TestCapitalizationFilter.java b/src/test/org/apache/solr/analysis/TestCapitalizationFilter.java
index 7e13787a5f0..a2798a7332d 100644
--- a/src/test/org/apache/solr/analysis/TestCapitalizationFilter.java
+++ b/src/test/org/apache/solr/analysis/TestCapitalizationFilter.java
@@ -17,6 +17,8 @@
 
 package org.apache.solr.analysis;
 
+import junit.framework.TestCase;
+
 import java.util.HashMap;
 import java.util.Map;
 
@@ -115,5 +117,10 @@ public class TestCapitalizationFilter extends BaseTokenTestCase {
     termBuffer = "kiTTEN".toCharArray();
     factory.processWord(termBuffer, 0, termBuffer.length, 0 );
     assertEquals( "kiTTEN",  new String(termBuffer, 0, termBuffer.length));
+
+    factory.keep = null;
+    termBuffer = "kiTTEN".toCharArray();
+    factory.processWord(termBuffer, 0, termBuffer.length, 0 );
+    assertEquals( "Kitten",  new String(termBuffer, 0, termBuffer.length));
   }
 }