diff --git a/src/SelectQuery.php b/src/SelectQuery.php
index 95a5e5487c16bdb8d749e8c53a358ec9f3b3c600..86373b7f944e33e35bbaaee4c9557edf011cd298 100644
--- a/src/SelectQuery.php
+++ b/src/SelectQuery.php
@@ -59,11 +59,15 @@ class SelectQuery implements SelectQueryInterface {
    */
   public function __construct($object_type = '') {
     $this->objectType = $object_type;
+    $this->conjunction = 'AND';
   }
 
   /**
    * Add a condition to the query.
    *
+   * Conditions will be combined with the conjunction defined by
+   * $this->conjunction. Defaults to 'AND'.
+   *
    * @param string $field
    *   Field name.
    * @param mixed $value
@@ -100,6 +104,8 @@ class SelectQuery implements SelectQueryInterface {
    * Implements PHP's magic toString().
    *
    * Function to convert the query to a string to pass to the SF API.
+   * Conditions will be combined with the conjunction defined by
+   * $this->conjunction. Defaults to 'AND'.
    *
    * @return string
    *   SOQL query ready to be executed the SF API.
@@ -116,7 +122,7 @@ class SelectQuery implements SelectQueryInterface {
       foreach ($this->conditions as $condition) {
         $where[] = implode('+', $condition);
       }
-      $query .= '+WHERE+' . implode('+AND+', $where);
+      $query .= '+WHERE+' . implode('+' . $this->conjunction . '+', $where);
     }
 
     if ($this->order) {