diff --git a/src/Illuminate/Database/Eloquent/Builder.php b/src/Illuminate/Database/Eloquent/Builder.php
index fd9919ef05ef..b053f3819e5f 100755
--- a/src/Illuminate/Database/Eloquent/Builder.php
+++ b/src/Illuminate/Database/Eloquent/Builder.php
@@ -822,10 +822,15 @@ protected function addUpdatedAtColumn(array $values)
             return $values;
         }
 
-        return Arr::add(
-            $values, $this->model->getUpdatedAtColumn(),
-            $this->model->freshTimestampString()
-        );
+        if (count($this->getQuery()->joins) > 0) {
+            $column = $this->model->getQualifiedUpdatedAtColumn();
+        } else {
+            $column = $this->model->getUpdatedAtColumn();
+        }
+
+        return array_merge($values, [
+            $column => $this->model->freshTimestampString(),
+        ]);
     }
 
     /**
diff --git a/src/Illuminate/Database/Eloquent/Concerns/HasTimestamps.php b/src/Illuminate/Database/Eloquent/Concerns/HasTimestamps.php
index ce3e0801dee6..fb355c5bf217 100644
--- a/src/Illuminate/Database/Eloquent/Concerns/HasTimestamps.php
+++ b/src/Illuminate/Database/Eloquent/Concerns/HasTimestamps.php
@@ -122,4 +122,14 @@ public function getUpdatedAtColumn()
     {
         return static::UPDATED_AT;
     }
+
+    /**
+     * Get the fully qualified "updated at" column.
+     *
+     * @return string
+     */
+    public function getQualifiedUpdatedAtColumn()
+    {
+        return $this->getTable().'.'.$this->getUpdatedAtColumn();
+    }
 }