diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 123c6f12..f7fe9133 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -17,7 +17,6 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.0'
           - '1.6'
           - '1' # automatically expands to the latest stable 1.x release of Julia
         os:
diff --git a/Project.toml b/Project.toml
index f8d46189..0cf3f22d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -13,9 +13,9 @@ ScikitLearnBase = "6e75b9c4-186b-50bd-896f-2d2496a4843e"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 
 [compat]
-AbstractTrees = "0.3"
+AbstractTrees = "0.3, 0.4"
 ScikitLearnBase = "0.5"
-julia = "1"
+julia = "1.6"
 
 [extras]
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"