diff --git includes/database/pgsql/database.inc includes/database/pgsql/database.inc
index dbb3286..c4f948a 100644
--- includes/database/pgsql/database.inc
+++ includes/database/pgsql/database.inc
@@ -188,6 +188,30 @@ class DatabaseConnection_pgsql extends DatabaseConnection {
 
     return $id;
   }
+
+  /**
+   * Overrides PDO::lastInsertId().
+   *
+   * Catchs and handles the exception in case currval() fails.
+   */
+  public function lastInsertId($name = null) {
+    try {
+      return parent::lastInsertId($name);
+    } catch(PDOException $e) {
+      if ($e->getCode() == 55000) {
+        // This fail if a value was inserted into the serial column and
+        // nextval() was never called. In that case, the last_insert_id is known
+        // by the caller and NULL is returned.
+        $last_insert_id = NULL;
+      }
+      else {
+        // If it is a different exception, re-throw it.
+        throw $e;
+      }
+    }
+    return $last_insert_id;
+  }
+
 }
 
 /**
diff --git includes/database/pgsql/query.inc includes/database/pgsql/query.inc
index 8825229..5ed92ed 100644
--- includes/database/pgsql/query.inc
+++ includes/database/pgsql/query.inc
@@ -69,6 +69,16 @@ class InsertQuery_pgsql extends InsertQuery {
     }
     $last_insert_id = $this->connection->query($stmt, array(), $options);
 
+    // If a value was inserted into a serial column, update the sequence.
+    if (!empty($table_information->serial_fields)) {
+      foreach ($table_information->serial_fields as $index => $serial_field) {
+        if (in_array($serial_field, $this->insertFields)) {
+          $curval = $this->connection->query("SELECT MAX(" . $serial_field . ") FROM {" . $this->table . "}")->fetchField();
+          $this->connection->query("SELECT SETVAL('" . $table_information->sequences[$index] . "', :curval)", array(':curval' => $curval));
+        }
+      }
+    }
+
     // Re-initialize the values array so that we can re-use this query.
     $this->insertValues = array();