diff --git a/docs/Project.toml b/docs/Project.toml
index e4442fc..3adf724 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -28,7 +28,7 @@ Documenter = "1"
 ForwardDiff = "0.10"
 KernelDensity = "0.6"
 MCMCChains = "6"
-Optimization = "3"
+Optimization = "3, 4"
 OptimizationMOI = "0.1, 0.2, 0.3, 0.4, 0.5"
 OptimizationNLopt = "0.1, 0.2, 0.3"
 OrdinaryDiffEq = "6"