diff --git a/changelog.d/6985.misc b/changelog.d/6985.misc
new file mode 100644
index 000000000000..ba367fa9af13
--- /dev/null
+++ b/changelog.d/6985.misc
@@ -0,0 +1 @@
+Update warning for incorrect database collation/ctype to include link to documentation.
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index a077345960a9..53b3f372b06d 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -53,7 +53,7 @@ def check_database(self, db_conn, allow_outdated_version: bool = False):
             if rows and rows[0][0] != "UTF8":
                 raise IncorrectDatabaseSetup(
                     "Database has incorrect encoding: '%s' instead of 'UTF8'\n"
-                    "See docs/postgres.rst for more information." % (rows[0][0],)
+                    "See docs/postgres.md for more information." % (rows[0][0],)
                 )
 
             txn.execute(
@@ -62,12 +62,16 @@ def check_database(self, db_conn, allow_outdated_version: bool = False):
             collation, ctype = txn.fetchone()
             if collation != "C":
                 logger.warning(
-                    "Database has incorrect collation of %r. Should be 'C'", collation
+                    "Database has incorrect collation of %r. Should be 'C'\n"
+                    "See docs/postgres.md for more information.",
+                    collation,
                 )
 
             if ctype != "C":
                 logger.warning(
-                    "Database has incorrect ctype of %r. Should be 'C'", ctype
+                    "Database has incorrect ctype of %r. Should be 'C'\n"
+                    "See docs/postgres.md for more information.",
+                    ctype,
                 )
 
     def check_new_database(self, txn):