diff --git a/PIL/PngImagePlugin.py b/PIL/PngImagePlugin.py
index 5e5eb14c7..e329a6c0d 100644
--- a/PIL/PngImagePlugin.py
+++ b/PIL/PngImagePlugin.py
@@ -113,7 +113,8 @@ class ChunkStream(object):
             length = i32(s)
 
         if not is_cid(cid):
-            raise SyntaxError("broken PNG file (chunk %s)" % repr(cid))
+            if not ImageFile.LOAD_TRUNCATED_IMAGES:
+                raise SyntaxError("broken PNG file (chunk %s)" % repr(cid))
 
         return cid, pos, length