diff --git a/Project.toml b/Project.toml
index 3d01302d..8878e8a9 100644
--- a/Project.toml
+++ b/Project.toml
@@ -23,7 +23,7 @@ DiffEqBase = "6.152"
 ForwardDiff = "0.10"
 IfElse = "0.1"
 LinearAlgebra = "1.10"
-ModelingToolkit = "10"
+ModelingToolkit = "10, 9"
 OrdinaryDiffEq = "6.87"
 OrdinaryDiffEqDefault = "1.1"
 PreallocationTools = "0.4.23"