diff --git a/oletools/rtfobj.py b/oletools/rtfobj.py
index dad78c3..b2f9384 100644
--- a/oletools/rtfobj.py
+++ b/oletools/rtfobj.py
@@ -499,6 +499,9 @@ class RtfParser(object):
 
     def _bin(self, matchobject, param):
         binlen = int(param)
+        if binlen < 0:
+            binlen = int(param.strip('-'))
+            
         log.debug('\\bin: reading %d bytes of binary data' % binlen)
         # TODO: handle optional space?
         # TODO: handle negative length, and length greater than data