diff --git a/query_classifier/test/maxscale.test b/query_classifier/test/maxscale.test
index a0d037df2..63fed3f4c 100644
--- a/query_classifier/test/maxscale.test
+++ b/query_classifier/test/maxscale.test
@@ -100,3 +100,6 @@ SELECT '2005-01-01' - INTERVAL 1 SECOND;
 
 # MXS-1730
 SELECT id as engine FROM users WHERE id = 1;
+
+# MXS-1787
+CALL p1((SELECT f1()), ?);