diff --git a/serveradmin/serverdb/migrations/0007_hostname_regex_hyphens.py b/serveradmin/serverdb/migrations/0007_hostname_regex_hyphens.py
index 6b0e0d81..72d78666 100644
--- a/serveradmin/serverdb/migrations/0007_hostname_regex_hyphens.py
+++ b/serveradmin/serverdb/migrations/0007_hostname_regex_hyphens.py
@@ -26,13 +26,13 @@ class Migration(migrations.Migration):
                 "ALTER TABLE server "
                 "DROP CONSTRAINT server_hostname_check, "
                 "ADD CONSTRAINT server_hostname_check "
-                "CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+(\.|-+))*[a-z0-9]+\Z'::text);"
+                r"CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+(\.|-+))*[a-z0-9]+\Z'::text);"
             ),
             reverse_sql=(
                 "ALTER TABLE server "
                 "DROP CONSTRAINT server_hostname_check, "
                 "ADD CONSTRAINT server_hostname_check "
-                "CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+[\.\-])*[a-z0-9]+\Z'::text);"
+                r"CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+[\.\-])*[a-z0-9]+\Z'::text);"
             )
         ),
     ]
diff --git a/serveradmin/serverdb/migrations/0018_alter_server_hostname.py b/serveradmin/serverdb/migrations/0018_alter_server_hostname.py
index bcc3aad1..3c1f115a 100644
--- a/serveradmin/serverdb/migrations/0018_alter_server_hostname.py
+++ b/serveradmin/serverdb/migrations/0018_alter_server_hostname.py
@@ -21,13 +21,13 @@ class Migration(migrations.Migration):
                 "ALTER TABLE server "
                 "DROP CONSTRAINT server_hostname_check, "
                 "ADD CONSTRAINT server_hostname_check "
-                "CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9_]+(\.|-+))*[a-z0-9]+\Z'::text);"
+                r"CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9_]+(\.|-+))*[a-z0-9]+\Z'::text);"
             ),
             reverse_sql=(
                 "ALTER TABLE server "
                 "DROP CONSTRAINT server_hostname_check, "
                 "ADD CONSTRAINT server_hostname_check "
-                "CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+(\.|-+))*[a-z0-9]+\Z'::text);"
+                r"CHECK (hostname::text ~ '\A(\*\.)?([a-z0-9]+(\.|-+))*[a-z0-9]+\Z'::text);"
             )
         ),
     ]
diff --git a/serveradmin/serverdb/sql_generator.py b/serveradmin/serverdb/sql_generator.py
index 57ad037e..039298ef 100644
--- a/serveradmin/serverdb/sql_generator.py
+++ b/serveradmin/serverdb/sql_generator.py
@@ -243,8 +243,8 @@ def _condition_sql(attribute, template, related_vias):
     if attribute.type == 'domain':
         return _exists_sql(Server, 'sub', (
             _target_servertype_sql('sub', attribute),
-            "server.hostname ~ ('\\A[^\.]+\.' || regexp_replace("
-            "sub.hostname, '(\*|\-|\.)', '\\\1', 'g') || '\\Z')",
+            r"server.hostname ~ ('\A[^\.]+\.' || regexp_replace("
+            r"sub.hostname, '(\*|\-|\.)', '\\\1', 'g') || '\Z')",
             template.format('sub.server_id'),
         ))
     if attribute.type == 'reverse':