diff --git a/Project.toml b/Project.toml
index 6d81cefd7..003ca5d79 100644
--- a/Project.toml
+++ b/Project.toml
@@ -70,7 +70,7 @@ GeometryBasics = "0.3, 0.4"
 HTTP = "0.8, 0.9"
 ImageView = "0.10"
 Images = "0.23, 0.24, 0.25"
-Ipopt = "0.6, 0.7, 0.8"
+Ipopt = "0.6, 0.7, 0.8, 0.9"
 JSServe = "1"
 JuMP = "0.21, 0.22"
 LazySets = "1"