diff --git a/src/main/java/org/elasticsearch/index/analysis/TurkishStemmerTokenFilterFactory.java b/src/main/java/org/elasticsearch/index/analysis/TurkishStemmerTokenFilterFactory.java
index 0bd632e..fcdd467 100644
--- a/src/main/java/org/elasticsearch/index/analysis/TurkishStemmerTokenFilterFactory.java
+++ b/src/main/java/org/elasticsearch/index/analysis/TurkishStemmerTokenFilterFactory.java
@@ -95,6 +95,9 @@ private CharArraySet parseAverageStemSizeExceptions(Environment env,
 
   private CharArraySet parseExceptions(Environment env, Settings settings, String settingPrefix) {
     List<String> exceptionsList  = Analysis.getWordList(env, settings, settingPrefix);
+    if (exceptionsList == null) {
+      return null;
+    }
     if (exceptionsList.isEmpty()) {
       return CharArraySet.EMPTY_SET;
     } else {