diff --git a/Project.toml b/Project.toml
index ad11e5dc2..5b2298383 100644
--- a/Project.toml
+++ b/Project.toml
@@ -48,7 +48,7 @@ DocumenterTools = "0.1.13"
 GLPK = "0.14.12"
 Gurobi = "0.11"
 Ipopt = "0.7.0"
-JuMP = "0.21.8"
+JuMP = "0.21.8, 1"
 MathOptInterface = "1"
 MathProgBase = "0.7.8"
 OrdinaryDiffEq = "5.60.1, 6"