diff --git a/Project.toml b/Project.toml
index 960b36d..06937a7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -11,7 +11,7 @@ Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 [compat]
 DiffEqBase = "6.5"
 MATLAB = "0.7"
-ModelingToolkit = "1.4.2, 2.0, 3.0"
+ModelingToolkit = "1.4.2, 2.0, 3.0, 4.0"
 Reexport = "0.2"
 julia = "1"