diff --git a/content/base/public/nsIDocumentEncoder.idl b/content/base/public/nsIDocumentEncoder.idl
index 78068ca57f27..2f60bc403027 100644
--- a/content/base/public/nsIDocumentEncoder.idl
+++ b/content/base/public/nsIDocumentEncoder.idl
@@ -187,7 +187,7 @@ interface nsIDocumentEncoder : nsISupports
   const unsigned long OutputEncodeHTMLEntities = (1 << 16);
 
   /**
-   * Normally &npsp; is replaced with a space character when
+   * Normally &nbsp; is replaced with a space character when
    * encoding data as plain text, set this flag if that's
    * not desired.
    */