diff --git a/Project.toml b/Project.toml
index 6cc4d634..b0c97bcd 100644
--- a/Project.toml
+++ b/Project.toml
@@ -41,7 +41,7 @@ Parameters = "~0.12"
 Plasmo = "~0.3"
 SolverTools = "~0.3"
 StaticArrays = "~0.12"
-julia = "1"
+julia = "1.5"
 
 [extras]
 AmplNLReader = "77dd3d4c-cb1d-5e09-9340-85030ff7ba66"