diff --git a/test/downstream/Project.toml b/test/downstream/Project.toml
index 0f43ffcf9..ae65f95a5 100644
--- a/test/downstream/Project.toml
+++ b/test/downstream/Project.toml
@@ -7,4 +7,5 @@ Unitful = "1986cc42-f94f-5a68-af5c-568840ba703d"
 [compat]
 ModelingToolkit = "8.33, 9"
 ParameterizedFunctions = "5.15"
+Symbolics = "5"
 Unitful = "1"