diff --git a/CHANGES.txt b/CHANGES.txt
index d29f6f53676..ffec8168828 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -13,6 +13,8 @@ Avro 1.3.3 (Unreleased)
 
     AVRO-496. python sample_http_client.py is broken (Jeff Hodges via hammer)
 
+    AVRO-527. Undefined variable "schm" error (Esteve Fernandez via hammer)
+
 Avro 1.3.2 (31 March 2010)
 
   IMPROVEMENTS
diff --git a/lang/py/src/avro/io.py b/lang/py/src/avro/io.py
index f156ccaf6fd..ce892053901 100644
--- a/lang/py/src/avro/io.py
+++ b/lang/py/src/avro/io.py
@@ -487,7 +487,7 @@ def skip_data(self, writers_schema, decoder):
     elif writers_schema.type in ['record', 'error', 'request']:
       return self.skip_record(writers_schema, decoder)
     else:
-      fail_msg = "Unknown schema type: %s" % schm.type
+      fail_msg = "Unknown schema type: %s" % writers_schema.type
       raise schema.AvroException(fail_msg)
 
   def read_fixed(self, writers_schema, readers_schema, decoder):