diff --git a/hy_odoo/test.hy b/hy_odoo/test.hy
index bf1c5aa..a1b6ec2 100644
--- a/hy_odoo/test.hy
+++ b/hy_odoo/test.hy
@@ -21,6 +21,7 @@
 (defmacro o-assert-true [val] `(.assertTrue self ~val))
 (defmacro o-assert-false [val] `(.assertFalse self ~val))
 (defmacro o-assert-in [left right] `(.assertIn self ~left ~right))
+(defmacro o-assert-not-in [left right] `(.assertNotIn self ~left ~right))
 (defmacro o-assert-raises [Error] `(.assertRaises self ~Error))
 
 (defmacro odo-assert-raises [Error body]