diff --git a/resources/sql/autopatches/20180828.phriction.06.c.documentid.php b/resources/sql/autopatches/20180828.phriction.06.c.documentid.php
new file mode 100644
index 0000000000..474643d620
--- /dev/null
+++ b/resources/sql/autopatches/20180828.phriction.06.c.documentid.php
@@ -0,0 +1,20 @@
+<?php
+
+// See T13193. We're about to drop the "documentID" column, which is part of
+// a UNIQUE KEY. In MariaDB, we must first drop the "documentID" key or we get
+// into deep trouble.
+
+// There's no "IF EXISTS" modifier for "ALTER TABLE" so run this as a PHP patch
+// instead of an SQL patch.
+
+$table = new PhrictionContent();
+$conn = $table->establishConnection('w');
+
+try {
+  queryfx(
+    $conn,
+    'ALTER TABLE %T DROP KEY documentID',
+    $table->getTableName());
+} catch (AphrontQueryException $ex) {
+  // Ignore.
+}
diff --git a/resources/sql/autopatches/20180828.phriction.07.documentkey.sql b/resources/sql/autopatches/20180828.phriction.07.documentkey.sql
new file mode 100644
index 0000000000..aea3c97130
--- /dev/null
+++ b/resources/sql/autopatches/20180828.phriction.07.documentkey.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_phriction.phriction_content
+  ADD UNIQUE KEY `key_version` (documentPHID, version);
diff --git a/src/applications/phriction/storage/PhrictionContent.php b/src/applications/phriction/storage/PhrictionContent.php
index 287974715f..5c597ab885 100644
--- a/src/applications/phriction/storage/PhrictionContent.php
+++ b/src/applications/phriction/storage/PhrictionContent.php
@@ -1,139 +1,139 @@
 <?php
 
 final class PhrictionContent
   extends PhrictionDAO
   implements
     PhabricatorPolicyInterface,
     PhabricatorDestructibleInterface,
     PhabricatorConduitResultInterface {
 
   protected $documentPHID;
   protected $version;
   protected $authorPHID;
 
   protected $title;
   protected $slug;
   protected $content;
   protected $description;
 
   protected $changeType;
   protected $changeRef;
 
   private $document = self::ATTACHABLE;
 
   protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_COLUMN_SCHEMA => array(
         'version' => 'uint32',
         'title' => 'sort',
         'slug' => 'text128',
         'content' => 'text',
         'changeType' => 'uint32',
         'changeRef' => 'uint32?',
         'description' => 'text',
       ),
       self::CONFIG_KEY_SCHEMA => array(
-        'documentID' => array(
+        'key_version' => array(
           'columns' => array('documentPHID', 'version'),
           'unique' => true,
         ),
         'authorPHID' => array(
           'columns' => array('authorPHID'),
         ),
         'slug' => array(
           'columns' => array('slug'),
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function getPHIDType() {
     return PhrictionContentPHIDType::TYPECONST;
   }
 
   public function newRemarkupView(PhabricatorUser $viewer) {
     return id(new PHUIRemarkupView($viewer, $this->getContent()))
       ->setContextObject($this)
       ->setRemarkupOption(PHUIRemarkupView::OPTION_GENERATE_TOC, true)
       ->setGenerateTableOfContents(true);
   }
 
   public function attachDocument(PhrictionDocument $document) {
     $this->document = $document;
     return $this;
   }
 
   public function getDocument() {
     return $this->assertAttached($this->document);
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
     );
   }
 
   public function getPolicy($capability) {
     return PhabricatorPolicies::getMostOpenPolicy();
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return false;
   }
 
 
 /* -(  PhabricatorExtendedPolicyInterface  )--------------------------------- */
 
 
   public function getExtendedPolicy($capability, PhabricatorUser $viewer) {
     return array(
       array($this->getDocument(), PhabricatorPolicyCapability::CAN_VIEW),
     );
   }
 
 
 /* -(  PhabricatorDestructibleInterface  )----------------------------------- */
 
 
   public function destroyObjectPermanently(
     PhabricatorDestructionEngine $engine) {
     $this->delete();
   }
 
 
 /* -(  PhabricatorConduitResultInterface  )---------------------------------- */
 
 
   public function getFieldSpecificationsForConduit() {
     return array(
       id(new PhabricatorConduitSearchFieldSpecification())
         ->setKey('documentPHID')
         ->setType('phid')
         ->setDescription(pht('Document this content is for.')),
       id(new PhabricatorConduitSearchFieldSpecification())
         ->setKey('version')
         ->setType('int')
         ->setDescription(pht('Content version.')),
     );
   }
 
   public function getFieldValuesForConduit() {
     return array(
       'documentPHID' => $this->getDocument()->getPHID(),
       'version' => (int)$this->getVersion(),
     );
   }
 
   public function getConduitSearchAttachments() {
     return array(
       id(new PhrictionContentSearchEngineAttachment())
         ->setAttachmentKey('content'),
     );
   }
 
 }