diff --git a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/org/apache/hyracks/storage/am/lsm/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/org/apache/hyracks/storage/am/lsm/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
index 4c486c5..8bd0c50 100644
--- a/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/org/apache/hyracks/storage/am/lsm/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
+++ b/hyracks-fullstack/hyracks/hyracks-storage-am-lsm-invertedindex/src/main/java/org/apache/hyracks/storage/am/lsm/invertedindex/tokenizers/NGramUTF8StringBinaryTokenizer.java
@@ -110,7 +110,11 @@
         if (usePrePost) {
             totalGrams = numChars + gramLength - 1;
         } else {
-            totalGrams = numChars - gramLength + 1;
+            if (numChars >= gramLength) {
+                totalGrams = numChars - gramLength + 1;
+            } else {
+                totalGrams = 0;
+            }
         }
     }