diff --git a/synapse/storage/__init__.py b/synapse/storage/__init__.py
index 75af44d78..71757c393 100644
--- a/synapse/storage/__init__.py
+++ b/synapse/storage/__init__.py
@@ -348,7 +348,7 @@ def _upgrade_existing_database(cur, current_version, applied_delta_files,
                         module_name, absolute_path, python_file
                     )
                 logger.debug("Running script %s", relative_path)
-                module.run_upgrade(cur)
+                module.run_upgrade(cur, database_engine)
             elif ext == ".sql":
                 # A plain old .sql file, just read and execute it
                 logger.debug("Applying schema %s", relative_path)
diff --git a/synapse/storage/schema/delta/14/upgrade_appservice_db.py b/synapse/storage/schema/delta/14/upgrade_appservice_db.py
index 9f3a4dd4c..61232f975 100644
--- a/synapse/storage/schema/delta/14/upgrade_appservice_db.py
+++ b/synapse/storage/schema/delta/14/upgrade_appservice_db.py
@@ -18,7 +18,7 @@ import logging
 logger = logging.getLogger(__name__)
 
 
-def run_upgrade(cur):
+def run_upgrade(cur, *args, **kwargs):
     cur.execute("SELECT id, regex FROM application_services_regex")
     for row in cur.fetchall():
         try:
diff --git a/synapse/storage/schema/delta/20/pushers.py b/synapse/storage/schema/delta/20/pushers.py
new file mode 100644
index 000000000..f09b41559
--- /dev/null
+++ b/synapse/storage/schema/delta/20/pushers.py
@@ -0,0 +1,77 @@
+# Copyright 2015 OpenMarket Ltd
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+"""
+Main purpose of this upgrade is to change the unique key on the
+pushers table again (it was missed when the v16 full schema was
+made) but this also changes the pushkey and data columns to text.
+When selecting a bytea column into a text column, postgres inserts
+the hex encoded data, and there's no portable way of getting the
+UTF-8 bytes, so we have to do it in Python.
+"""
+
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def run_upgrade(cur, database_engine, *args, **kwargs):
+    logger.info("Porting pushers table...")
+    cur.execute("""
+        CREATE TABLE IF NOT EXISTS pushers2 (
+          id BIGINT PRIMARY KEY,
+          user_name TEXT NOT NULL,
+          access_token BIGINT DEFAULT NULL,
+          profile_tag VARCHAR(32) NOT NULL,
+          kind VARCHAR(8) NOT NULL,
+          app_id VARCHAR(64) NOT NULL,
+          app_display_name VARCHAR(64) NOT NULL,
+          device_display_name VARCHAR(128) NOT NULL,
+          pushkey TEXT NOT NULL,
+          ts BIGINT NOT NULL,
+          lang VARCHAR(8),
+          data TEXT,
+          last_token TEXT,
+          last_success BIGINT,
+          failing_since BIGINT,
+          UNIQUE (app_id, pushkey, user_name)
+        )
+    """)
+    cur.execute("""SELECT
+        id, user_name, access_token, profile_tag, kind,
+        app_id, app_display_name, device_display_name,
+        pushkey, ts, lang, data, last_token, last_success,
+        failing_since
+        FROM pushers
+    """)
+    count = 0
+    for row in cur.fetchall():
+        row = list(row)
+        row[8] = bytes(row[8]).decode("utf-8")
+        row[11] = bytes(row[11]).decode("utf-8")
+        cur.execute(database_engine.convert_param_style("""
+            INSERT into pushers2 (
+            id, user_name, access_token, profile_tag, kind,
+            app_id, app_display_name, device_display_name,
+            pushkey, ts, lang, data, last_token, last_success,
+            failing_since
+            ) values (%s)""" % (','.join(['?' for _ in range(len(row))]))),
+            row
+        )
+        count += 1
+    cur.execute("DROP TABLE pushers")
+    cur.execute("ALTER TABLE pushers2 RENAME TO pushers")
+    logger.info("Moved %d pushers to new table", count)
+