diff --git a/Project.toml b/Project.toml
index 57bdea3..a63c8c3 100755
--- a/Project.toml
+++ b/Project.toml
@@ -58,7 +58,7 @@ DecisionTree = "0.12"
 DelimitedFiles = "1"
 Hyperopt = "0.5"
 IterTools = "1"
-JSON = "0.21"
+JSON = "0.21, 1"
 LinearAlgebra = "1"
 Logging = "1.11"
 MLJDecisionTreeInterface = "0.4"