diff --git a/src/sqlite3_lib.erl b/src/sqlite3_lib.erl
index b2a6315..755db92 100644
--- a/src/sqlite3_lib.erl
+++ b/src/sqlite3_lib.erl
@@ -380,6 +380,7 @@ column_sql_for_create_table({Name, Type, Constraints}) ->
 pk_constraint_sql(Constraint) ->
   case Constraint of
     desc -> "DESC";
+    asc -> "ASC";
     autoincrement -> "AUTOINCREMENT";
     L -> lists:map(fun pk_constraint_sql/1, L)
   end.