diff --git a/lib/PostText.pm b/lib/PostText.pm
index 43c874f..51f7f5f 100644
--- a/lib/PostText.pm
+++ b/lib/PostText.pm
@@ -53,7 +53,7 @@ sub startup($self) {
     # Finish configuring some things
     $self->secrets($self->config->{'secrets'}) || die $@;
 
-    $self->pg->migrations->from_dir('migrations')->migrate(9);
+    $self->pg->migrations->from_dir('migrations')->migrate(10);
 
     if (my $threads_per_page = $self->config->{'threads_per_page'}) {
         $self->thread->per_page($threads_per_page)
diff --git a/migrations/10/down.sql b/migrations/10/down.sql
new file mode 100644
index 0000000..da31641
--- /dev/null
+++ b/migrations/10/down.sql
@@ -0,0 +1,3 @@
+ALTER TABLE moderators
+ DROP CONSTRAINT moderators_email_addr_key;
+
diff --git a/migrations/10/up.sql b/migrations/10/up.sql
new file mode 100644
index 0000000..48d25b4
--- /dev/null
+++ b/migrations/10/up.sql
@@ -0,0 +1,2 @@
+ALTER TABLE moderators
+  ADD UNIQUE (email_addr);