diff --git a/Project.toml b/Project.toml
index d7ddd87..a892fdc 100644
--- a/Project.toml
+++ b/Project.toml
@@ -34,7 +34,7 @@ Optimisers = "0.4"
 Parameters = "0.12, 0.13"
 ParticleMethods = "0.1"
 Plots = "1"
-PoissonSolvers = "0.1, 0.2, 0.3"
+PoissonSolvers = "0.1, 0.2, 0.3, 0.6"
 RecursiveArrayTools = "4"
 ReducedComplexityModeling = "0.1"
 Statistics = "1"