diff --git a/src/main/java/org/apache/commons/math3/exception/NotANumberException.java b/src/main/java/org/apache/commons/math3/exception/NotANumberException.java
index cd1a6f82b..c5c44ee80 100644
--- a/src/main/java/org/apache/commons/math3/exception/NotANumberException.java
+++ b/src/main/java/org/apache/commons/math3/exception/NotANumberException.java
@@ -19,7 +19,7 @@ package org.apache.commons.math3.exception;
 import org.apache.commons.math3.exception.util.LocalizedFormats;
 
 /**
- * Exception to be thrown when a number is not a n umber.
+ * Exception to be thrown when a number is not a number.
  *
  * @since 3.0
  * @version $Id$