diff --git a/Project.toml b/Project.toml
index c8bdbe96..ea1048e0 100644
--- a/Project.toml
+++ b/Project.toml
@@ -67,7 +67,7 @@ Hankel = "0.5.5"
 Memoize = "0.4.4"
 NumericalIntegration = "0.3.3"
 Optim = "1.4"
-Peaks = "0.3.2"
+Peaks = "0.3.2, 0.4"
 PhysicalConstants = "0.2"
 Pidfile = "1.2"
 Polynomials = "2"