diff --git a/src/db/connection.cr b/src/db/connection.cr
index ddd61a9..469f62d 100644
--- a/src/db/connection.cr
+++ b/src/db/connection.cr
@@ -1,4 +1,8 @@
 module DB
+  class Database; end
+
+  abstract class Statement; end
+
   # Database driver implementors must subclass `Connection`.
   #
   # Represents one active connection to a database.