diff --git a/Project.toml b/Project.toml
index b0b5ce93..bfd9a2e2 100644
--- a/Project.toml
+++ b/Project.toml
@@ -17,7 +17,7 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 LDLFactorizations = "^0.4"
 MathOptInterface = "~0.9.5"
 OrderedCollections = "1"
-julia = "1"
+julia = "< 1.4"
 
 [extras]
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"