diff --git a/pyghmi/ipmi/oem/lenovo/imm.py b/pyghmi/ipmi/oem/lenovo/imm.py
index beca24c1..d99d7227 100644
--- a/pyghmi/ipmi/oem/lenovo/imm.py
+++ b/pyghmi/ipmi/oem/lenovo/imm.py
@@ -46,6 +46,8 @@ def fixup_uuid(uuidprop):
 
 
 def fixup_str(propstr):
+    if propstr is None:
+        return ''
     return ''.join([chr(int(c, 16)) for c in propstr.split()]).strip(
         ' \xff\x00')