diff --git a/.github/workflows/check_code_style.yml b/.github/workflows/check_code_style.yml
index c79cc520c..fb4546682 100644
--- a/.github/workflows/check_code_style.yml
+++ b/.github/workflows/check_code_style.yml
@@ -11,7 +11,7 @@ jobs:
       - name: Setup Flutter
         uses: subosito/flutter-action@v1
         with:
-          channel: "stable"
+          channel: "beta"
       - name: Check formattting
         run: flutter format --set-exit-if-changed --dry-run --line-length 100 .
       - name: Get packages
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index eefba3aee..f8445abaa 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -11,7 +11,7 @@ jobs:
       - name: Setup Flutter
         uses: subosito/flutter-action@v1
         with:
-          channel: "stable"
+          channel: "beta"
       - name: Get packages
         run: flutter pub get
       - name: Run tests
diff --git a/.metadata b/.metadata
index 5ab1e9a74..7d1d1dc3a 100644
--- a/.metadata
+++ b/.metadata
@@ -5,6 +5,6 @@
 
 version:
   revision: 7a4c33425ddd78c54aba07d86f3f9a4a0051769b
-  channel: stable
+  channel: beta
 
 project_type: package
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e0464db2d..3926ca05a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
-## Null Safety
-* [BREAKING] You cannot set null value on FlSpot anymore.
+## 0.20.0-nullsafety1
+* [BREAKING] **We have migrated our project to null-safety. You may need to change your source-code to compile**. check [migration guide](https://dart.dev/null-safety/migration-guide).
+* [BREAKING] You cannot set null value on FlSpot any more (use FlSpot.nullSpot instead).
 
 ## 0.12.3
 * [Bugfix] Fixed PieChart exception bug on sections tap, #514.
diff --git a/README.md b/README.md
index 22ffe827a..d9f83cd18 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ Thank you all!
 
 ```yml
 dependencies:
-  fl_chart: ^0.12.3
+  fl_chart: ^0.20.0-nullsafety1
 ```
 
 
diff --git a/example/.metadata b/example/.metadata
index 1b5cec022..387ddb54d 100644
--- a/example/.metadata
+++ b/example/.metadata
@@ -5,6 +5,6 @@
 
 version:
   revision: 27321ebbad34b0a3fafe99fac037102196d655ff
-  channel: stable
+  channel: beta
 
 project_type: app
diff --git a/pubspec.yaml b/pubspec.yaml
index 3caf5639d..9e93cf9f9 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,10 +1,10 @@
 name: fl_chart
 description: A powerful Flutter chart library, currently supporting Line Chart, Bar Chart and Pie Chart.
-version: 0.12.3
+version: 0.20.0-nullsafety1
 homepage: https://github.com/imaNNeoFighT/fl_chart
 
 environment:
-  sdk: ">=2.12.0-0 <3.0.0"
+  sdk: ">=2.12.0-259.12.beta <3.0.0"
 
 dependencies:
   flutter: