diff --git a/engines/mysql.inc b/engines/mysql.inc
index f86aaa3..69bca67 100644
--- a/engines/mysql.inc
+++ b/engines/mysql.inc
@@ -20,10 +20,28 @@ class SchemaDatabaseSchema_mysql extends DatabaseSchema_mysql {
     return parent::createTableSql($name, $table);
   }
 
+  /**
+   * Fetch the type map from the core and extend it to cover non Drupal types
+   */
+  public function schema_field_type_map() {
+    static $map;
+    if (!isset($map)) {
+      // Get the core map.
+      $map = $this->getFieldTypeMap();
+
+      // Add our extensions.
+      $map += array(
+        'datetime:normal'    => 'DATETIME',
+      );
+    }
+    return $map;
+  }
+
+
   public function schema_type_map() {
     static $map;
     if (!isset($map)) {
-      $map = array_flip(array_map('strtolower', $this->getFieldTypeMap()));
+      $map = array_flip(array_map('strtolower', $this->schema_field_type_map()));
     }
     return $map;
   }
diff --git a/engines/pgsql.inc b/engines/pgsql.inc
index 6accfa0..bfc1678 100644
--- a/engines/pgsql.inc
+++ b/engines/pgsql.inc
@@ -20,10 +20,24 @@ class SchemaDatabaseSchema_pgsql extends DatabaseSchema_pgsql {
     return parent::createTableSql($name, $table);
   }
 
+  /**
+   * Fetch the type map from the core and extend it to cover non Drupal types
+   */
+  public function schema_field_type_map() {
+    static $map;
+    if (!isset($map)) {
+      // Get the core map.
+      $map = $this->getFieldTypeMap();
+
+      // Add our extensions.
+    }
+    return $map;
+  }
+
   public function schema_type_map() {
     static $map;
     if (!isset($map)) {
-      $map = array_flip(array_map('strtolower', $this->getFieldTypeMap()));
+      $map = array_flip(array_map('strtolower', $this->schema_field_type_map()));
       $map['character varying'] = 'varchar:normal';
       $map['integer'] = 'int:normal';
     }
diff --git a/schema.module b/schema.module
index d1bf7ce..e4f0723 100755
--- a/schema.module
+++ b/schema.module
@@ -186,7 +186,7 @@ function schema_dbobject() {
  * Converts a column's Schema type into an engine-specific data type.
  */
 function schema_engine_type($col, $table, $field, $engine = NULL) {
-  $map = schema_dbobject()->getFieldTypeMap();
+  $map = schema_dbobject()->schema_field_type_map();
   $size = (isset($col['size']) ? $col['size'] : 'normal');
   $type = $col['type'] . ':' . $size;
   if (isset($map[$type])) {