diff --git a/poppler/JBIG2Stream.cc b/poppler/JBIG2Stream.cc
index 4853588..d89108c 100644
--- a/poppler/JBIG2Stream.cc
+++ b/poppler/JBIG2Stream.cc
@@ -896,7 +896,7 @@
   oneByte = x0 == ((x1 - 1) & ~7);
 
   for (yy = y0; yy < y1; ++yy) {
-    if (unlikely(y + yy) >= h)
+    if (unlikely((y + yy >= h) || (y + yy < 0)))
       continue;
 
     // one byte per line -- need to mask both left and right side