diff --git a/setup.py b/setup.py
index c7db0dd..eb3f66d 100755
--- a/setup.py
+++ b/setup.py
@@ -51,7 +51,7 @@ except:
 
 setuptools.setup(
         name='warcprox',
-        version='2.1b1.dev57',
+        version='2.1b1.dev58',
         description='WARC writing MITM HTTP/S proxy',
         url='https://github.com/internetarchive/warcprox',
         author='Noah Levitt',
diff --git a/warcprox/bigtable.py b/warcprox/bigtable.py
index c32a665..a61ce8b 100644
--- a/warcprox/bigtable.py
+++ b/warcprox/bigtable.py
@@ -159,7 +159,7 @@ class RethinkCaptures:
         else:
             bucket = "__unspecified__"
 
-        canon_surt = str(urlcanon.semantic(recorded_url.url))
+        canon_surt = urlcanon.semantic(recorded_url.url).surt().decode('ascii')
 
         entry = {
             # id only specified for rethinkdb partitioning