diff --git a/Project.toml b/Project.toml
index 7932362..9ff294a 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "BlackBoxOptim"
 uuid = "a134a8b2-14d6-55f6-9291-3336d3ab0209"
-version = "0.6.4"
+version = "0.6.3"
 
 [deps]
 CPUTime = "a9c8d775-2e2e-55fc-8582-045d282d599e"
@@ -31,6 +31,7 @@ JSON = "0.21"
 SpatialIndexing = "0.1.0"
 StatsBase = "0.33, 0.34"
 julia = "1.3.0"
+Requires = "1"
 
 [extras]
 CSV = "336ed68f-0bac-5ca0-87d4-7b16caf5d00b"