diff --git a/Project.toml b/Project.toml
index 9dfd094..39e8cff 100644
--- a/Project.toml
+++ b/Project.toml
@@ -31,7 +31,7 @@ Infiltrator = "1"
 JLD2 = "0.4"
 Muninn = "0.3"
 Optimization = "3"
-OptimizationOptimJL = "0.3"
+OptimizationOptimJL = "0.1.5"
 OrdinaryDiffEq = "6"
 PlotThemes = "3"
 Plots = "1"