diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1d250e6..6f3b495 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,7 +13,7 @@ jobs:
     strategy:
       matrix:
         version:
-          - '1.3'
+          - '1.6'
           - '1'
           - 'nightly'
         os:
@@ -26,9 +26,9 @@ jobs:
           # Remove some configurations from the build matrix to reduce CI time.
           # See https://github.com/marketplace/actions/setup-julia-environment
           # Don't test on all versions
-          - {os: 'macOS-latest', version: '1.3'}
+          - {os: 'macOS-latest', version: '1.6'}
           - {os: 'macOS-latest', version: 'nightly'}
-          - {os: 'windows-latest', version: '1.3'}
+          - {os: 'windows-latest', version: '1.6'}
           - {os: 'windows-latest', version: 'nightly'}
     steps:
       - uses: actions/checkout@v1
diff --git a/Project.toml b/Project.toml
index 396b36b..06471ba 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,6 +1,6 @@
 name = "XGBoost"
 uuid = "009559a3-9522-5dbb-924b-0b6ed2b22bb9"
-version = "1.1.1"
+version = "1.5.2"
 
 [deps]
 Libdl = "8f399da3-3557-5675-b5ff-fb832c97cbdb"
@@ -12,8 +12,8 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 XGBoost_jll = "a5c6f535-4255-5ca2-a466-0e519f119c46"
 
 [compat]
-XGBoost_jll = "1.1.1"
-julia = "1.3"
+XGBoost_jll = "1.5.2"
+julia = "1.6"
 
 [extras]
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
diff --git a/README.md b/README.md
index fefa925..72d251e 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 XGBoost.jl
 ==========
 
-[![Build Status](https://travis-ci.org/dmlc/XGBoost.jl.svg?branch=master)](https://travis-ci.org/dmlc/XGBoost.jl)
+[![Build Status](https://github.com/dmlc/XGBoost.jl/workflows/CI/badge.svg)](https://github.com/dmlc/XGBoost.jl/actions)
 [![Latest Version](https://juliahub.com/docs/XGBoost/version.svg)](https://juliahub.com/ui/Packages/XGBoost/rSeEh/)
 [![Pkg Eval](https://juliahub.com/docs/XGBoost/pkgeval.svg)](https://juliahub.com/ui/Packages/XGBoost/rSeEh/)
 [![Dependents](https://juliahub.com/docs/XGBoost/deps.svg)](https://juliahub.com/ui/Packages/XGBoost/rSeEh/?t=2)
diff --git a/test/dump.nice.json b/test/dump.nice.json
index abe933d..a2eea11 100644
--- a/test/dump.nice.json
+++ b/test/dump.nice.json
@@ -1,19 +1,19 @@
 [
-  { "nodeid": 0, "depth": 0, "split": "odor=none", "yes": 2, "no": 1, "gain": 4000.53101, "cover": 1628.25, "children": [
-    { "nodeid": 1, "depth": 1, "split": "stalk-root=club", "yes": 4, "no": 3, "gain": 1158.21204, "cover": 924.5, "children": [
-      { "nodeid": 3, "leaf": 1.71217716, "cover": 812 },
-      { "nodeid": 4, "leaf": -1.70044053, "cover": 112.5 }
-    ]},
-    { "nodeid": 2, "depth": 1, "split": "spore-print-color=green", "yes": 6, "no": 5, "gain": 198.173828, "cover": 703.75, "children": [
-      { "nodeid": 5, "leaf": -1.94070864, "cover": 690.5 },
-      { "nodeid": 6, "leaf": 1.85964918, "cover": 13.25 }
+  { "nodeid": 0, "depth": 0, "split": "odor=none", "yes": 2, "no": 1 , "gain": 4000.53101, "cover": 1628.25, "children": [
+    { "nodeid": 1, "depth": 1, "split": "stalk-root=club", "yes": 4, "no": 3 , "gain": 1158.21204, "cover": 924.5, "children": [
+      { "nodeid": 3, "leaf": 1.71217716 , "cover": 812 }, 
+      { "nodeid": 4, "leaf": -1.70044053 , "cover": 112.5 }
+    ]}, 
+    { "nodeid": 2, "depth": 1, "split": "spore-print-color=green", "yes": 6, "no": 5 , "gain": 198.173828, "cover": 703.75, "children": [
+      { "nodeid": 5, "leaf": -1.94070864 , "cover": 690.5 }, 
+      { "nodeid": 6, "leaf": 1.85964918 , "cover": 13.25 }
     ]}
   ]},
-  { "nodeid": 0, "depth": 0, "split": "stalk-root=rooted", "yes": 2, "no": 1, "gain": 832.545044, "cover": 788.852051, "children": [
-    { "nodeid": 1, "depth": 1, "split": "odor=none", "yes": 4, "no": 3, "gain": 569.725098, "cover": 768.389709, "children": [
-      { "nodeid": 3, "leaf": 0.78471756, "cover": 458.936859 },
-      { "nodeid": 4, "leaf": -0.968530357, "cover": 309.45282 }
-    ]},
-    { "nodeid": 2, "leaf": -6.23624468, "cover": 20.462389 }
+  { "nodeid": 0, "depth": 0, "split": "stalk-root=rooted", "yes": 2, "no": 1 , "gain": 832.545044, "cover": 788.852051, "children": [
+    { "nodeid": 1, "depth": 1, "split": "odor=none", "yes": 4, "no": 3 , "gain": 569.725098, "cover": 768.389709, "children": [
+      { "nodeid": 3, "leaf": 0.78471756 , "cover": 458.936859 }, 
+      { "nodeid": 4, "leaf": -0.968530357 , "cover": 309.45282 }
+    ]}, 
+    { "nodeid": 2, "leaf": -6.23624468 , "cover": 20.462389 }
   ]}
 ]
\ No newline at end of file
diff --git a/test/dump.nice.txt b/test/dump.nice.txt
index 8b2643b..4088158 100644
--- a/test/dump.nice.txt
+++ b/test/dump.nice.txt
@@ -1,14 +1,14 @@
 booster[1]:
 0:[odor=none] yes=2,no=1,gain=4000.53101,cover=1628.25
-	1:[stalk-root=club] yes=4,no=3,gain=1158.21204,cover=924.5
+1:[stalk-root=club] yes=4,no=3,gain=1158.21204,cover=924.5
 		3:leaf=1.71217716,cover=812
 		4:leaf=-1.70044053,cover=112.5
-	2:[spore-print-color=green] yes=6,no=5,gain=198.173828,cover=703.75
+2:[spore-print-color=green] yes=6,no=5,gain=198.173828,cover=703.75
 		5:leaf=-1.94070864,cover=690.5
 		6:leaf=1.85964918,cover=13.25
 booster[2]:
 0:[stalk-root=rooted] yes=2,no=1,gain=832.545044,cover=788.852051
-	1:[odor=none] yes=4,no=3,gain=569.725098,cover=768.389709
+1:[odor=none] yes=4,no=3,gain=569.725098,cover=768.389709
 		3:leaf=0.78471756,cover=458.936859
 		4:leaf=-0.968530357,cover=309.45282
 	2:leaf=-6.23624468,cover=20.462389
diff --git a/test/dump.raw.json b/test/dump.raw.json
index 1dd7644..425d3ab 100644
--- a/test/dump.raw.json
+++ b/test/dump.raw.json
@@ -1,19 +1,19 @@
 [
-  { "nodeid": 0, "depth": 0, "split": 28, "split_condition": -9.53674316e-07, "yes": 1, "no": 2, "missing": 1, "children": [
-    { "nodeid": 1, "depth": 1, "split": 55, "split_condition": -9.53674316e-07, "yes": 3, "no": 4, "missing": 3, "children": [
-      { "nodeid": 3, "leaf": 1.71217716 },
+  { "nodeid": 0, "depth": 0, "split": "f28", "split_condition": -9.53674316e-07, "yes": 1, "no": 2, "missing": 1 , "children": [
+    { "nodeid": 1, "depth": 1, "split": "f55", "split_condition": -9.53674316e-07, "yes": 3, "no": 4, "missing": 3 , "children": [
+      { "nodeid": 3, "leaf": 1.71217716 }, 
       { "nodeid": 4, "leaf": -1.70044053 }
-    ]},
-    { "nodeid": 2, "depth": 1, "split": 108, "split_condition": -9.53674316e-07, "yes": 5, "no": 6, "missing": 5, "children": [
-      { "nodeid": 5, "leaf": -1.94070864 },
+    ]}, 
+    { "nodeid": 2, "depth": 1, "split": "f108", "split_condition": -9.53674316e-07, "yes": 5, "no": 6, "missing": 5 , "children": [
+      { "nodeid": 5, "leaf": -1.94070864 }, 
       { "nodeid": 6, "leaf": 1.85964918 }
     ]}
   ]},
-  { "nodeid": 0, "depth": 0, "split": 59, "split_condition": -9.53674316e-07, "yes": 1, "no": 2, "missing": 1, "children": [
-    { "nodeid": 1, "depth": 1, "split": 28, "split_condition": -9.53674316e-07, "yes": 3, "no": 4, "missing": 3, "children": [
-      { "nodeid": 3, "leaf": 0.78471756 },
+  { "nodeid": 0, "depth": 0, "split": "f59", "split_condition": -9.53674316e-07, "yes": 1, "no": 2, "missing": 1 , "children": [
+    { "nodeid": 1, "depth": 1, "split": "f28", "split_condition": -9.53674316e-07, "yes": 3, "no": 4, "missing": 3 , "children": [
+      { "nodeid": 3, "leaf": 0.78471756 }, 
       { "nodeid": 4, "leaf": -0.968530357 }
-    ]},
+    ]}, 
     { "nodeid": 2, "leaf": -6.23624468 }
   ]}
 ]
\ No newline at end of file
diff --git a/test/xgb.model b/test/xgb.model
index 87e5210..f2db6e1 100644
Binary files a/test/xgb.model and b/test/xgb.model differ