diff --git a/tool_collections/gatk/unified_genotyper/gatk_wrapper.py b/tool_collections/gatk/unified_genotyper/gatk_wrapper.py
index 17e83798..1b067654 100644
--- a/tool_collections/gatk/unified_genotyper/gatk_wrapper.py
+++ b/tool_collections/gatk/unified_genotyper/gatk_wrapper.py
@@ -112,7 +112,7 @@ def __main__():
     while True:
         chunk = stderr.read( CHUNK_SIZE )
         if chunk:
-            stderr_target.write( chunk )
+            stderr_target.write( chunk.decode('utf-8') )
         else:
             break
     stderr.close()