diff --git a/poppler/JBIG2Stream.cc b/poppler/JBIG2Stream.cc
index d26ba02..067fb7f 100644
--- a/poppler/JBIG2Stream.cc
+++ b/poppler/JBIG2Stream.cc
@@ -15,7 +15,7 @@
 //
 // Copyright (C) 2006 Raj Kumar <rkumar@archive.org>
 // Copyright (C) 2006 Paul Walmsley <paul@booyaka.com>
-// Copyright (C) 2006-2010, 2012, 2014-2016 Albert Astals Cid <aacid@kde.org>
+// Copyright (C) 2006-2010, 2012, 2014-2017 Albert Astals Cid <aacid@kde.org>
 // Copyright (C) 2009 David Benjamin <davidben@mit.edu>
 // Copyright (C) 2011 Edward Jiang <ejiang@google.com>
 // Copyright (C) 2012 William Bader <williambader@hotmail.com>
@@ -1304,7 +1304,7 @@
 int JBIG2Stream::getChars(int nChars, Guchar *buffer) {
   int n, i;
 
-  if (nChars <= 0) {
+  if (nChars <= 0 || !dataPtr) {
     return 0;
   }
   if (dataEnd - dataPtr < nChars) {