2 files changed, 7 insertions, 3 deletions
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 1b97ee74e3..289b6bc281 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -45,6 +45,10 @@ class PostgresEngine(object):
         # together. For example, version 8.1.5 will be returned as 80105
         self._version = db_conn.server_version
 
+        # Are we on a supported PostgreSQL version?
+        if self._version < 90500:
+            raise RuntimeError("Synapse requires PostgreSQL 9.5+ or above.")
+
         db_conn.set_isolation_level(
             self.module.extensions.ISOLATION_LEVEL_REPEATABLE_READ
         )
@@ -64,9 +68,9 @@ class PostgresEngine(object):
     @property
     def can_native_upsert(self):
         """
-        Can we use native UPSERTs? This requires PostgreSQL 9.5+.
+        Can we use native UPSERTs?
         """
-        return self._version >= 90500
+        return True
 
     def is_deadlock(self, error):
         if isinstance(error, self.module.DatabaseError):
diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py
index 933bcf42c2..e9b9caa49a 100644
--- a/synapse/storage/engines/sqlite.py
+++ b/synapse/storage/engines/sqlite.py
@@ -85,7 +85,7 @@ class Sqlite3Engine(object):
 
 def _parse_match_info(buf):
     bufsize = len(buf)
-    return [struct.unpack('@I', buf[i : i + 4])[0] for i in range(0, bufsize, 4)]
+    return [struct.unpack("@I", buf[i : i + 4])[0] for i in range(0, bufsize, 4)]
 
 
 def _rank(raw_match_info):