diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 9aef1a4..b930c11 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.7'
+          - '1.6'
           - '1.10'
           - '1.12'
           - 'pre'
@@ -30,7 +30,7 @@ jobs:
           - 'x86'
         exclude:
           - os: macos-latest
-            version: '1.7'
+            version: '1.6'
           - os: macos-latest
             arch: 'x86'
     steps:
diff --git a/.github/workflows/CompatHelper.yml b/.github/workflows/CompatHelper.yml
deleted file mode 100644
index cba9134..0000000
--- a/.github/workflows/CompatHelper.yml
+++ /dev/null
@@ -1,16 +0,0 @@
-name: CompatHelper
-on:
-  schedule:
-    - cron: 0 0 * * *
-  workflow_dispatch:
-jobs:
-  CompatHelper:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Pkg.add("CompatHelper")
-        run: julia -e 'using Pkg; Pkg.add("CompatHelper")'
-      - name: CompatHelper.main()
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          COMPATHELPER_PRIV: ${{ secrets.DOCUMENTER_KEY }}
-        run: julia -e 'using CompatHelper; CompatHelper.main()'
diff --git a/Project.toml b/Project.toml
index a1b05dd..61ec084 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,10 +1,10 @@
 name = "MutatePlainDataArray"
 uuid = "3b0f367b-da20-4531-811a-c13cc92422b5"
 authors = ["Haoran Ni <haoranni@terpmail.umd.edu> and contributors"]
-version = "0.4.0"
+version = "1.0.0-dev"
 
 [compat]
-julia = "1.7"
+julia = "1.6"
 
 [workspace]
 projects = ["test"]
diff --git a/test/runtests.jl b/test/runtests.jl
index 29b01ac..91c3fa4 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -47,11 +47,11 @@ end
 
 @testset "MutatePlainDataArray.jl" begin
     @test isbitstype(TAB)
-    @test !isbitstype(TAI) && !ismutabletype(TAI)
-    @test ismutabletype(TAM)
+    @test !isbitstype(TAI)
+    @test !isbitstype(TAM)
     @test isbitstype(TBB)
-    @test !isbitstype(TBI) && !ismutabletype(TBI)
-    @test ismutabletype(TBM)
+    @test !isbitstype(TBI)
+    @test !isbitstype(TBM)
     @test isbitstype(TC)
 
     @testset "aref validation" begin