diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0d5f8df8f9..abd56f49da 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -37,6 +37,7 @@
 
 - **test-bin:** Only write output file in CI and fix trailing whitespaces ([#4613](https://github.com/ScoopInstaller/Scoop/issues/4613))
 - **manifest:** Fix manifests validation ([#4620](https://github.com/ScoopInstaller/Scoop/issues/4620))
+- **zstd:** Fix 'zstd' extraction error in test ([#4651](https://github.com/ScoopInstaller/Scoop/issues/4651))
 
 ### Documentation
 
diff --git a/appveyor.yml b/appveyor.yml
index 2ce7cfb803..5632ebbbb1 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -2,17 +2,13 @@ version: "{build}-{branch}"
 branches:
   except:
     - gh-pages
-build: off
-deploy: off
+build: false
+deploy: false
 clone_depth: 49
 image: Visual Studio 2019
 environment:
   scoop: C:\projects\scoop
   scoop_home: C:\projects\scoop
-  scoop_helpers: C:\projects\helpers
-  lessmsi: '%scoop_helpers%\lessmsi\lessmsi.exe'
-  innounp: '%scoop_helpers%\innounp\innounp.exe'
-  zstd: '%scoop_helpers%\zstd\zstd.exe'
   matrix:
     - PowerShell: 5
     - PowerShell: 6
diff --git a/test/Scoop-Decompress.Tests.ps1 b/test/Scoop-Decompress.Tests.ps1
index cad7d2a8f8..5a2a6e3e0d 100644
--- a/test/Scoop-Decompress.Tests.ps1
+++ b/test/Scoop-Decompress.Tests.ps1
@@ -80,7 +80,8 @@ Describe 'Decompression function' -Tag 'Scoop', 'Decompress' {
 
         BeforeAll {
             if ($env:CI) {
-                Mock Get-AppFilePath { $env:zstd }
+                Mock Get-AppFilePath { $env:SCOOP_ZSTD_PATH } -ParameterFilter { $Helper -eq 'zstd' }
+                Mock Get-AppFilePath { '7z.exe' } -ParameterFilter { $Helper -eq '7zip' }
             } elseif (!(installed zstd)) {
                 scoop install zstd
             }
@@ -114,7 +115,7 @@ Describe 'Decompression function' -Tag 'Scoop', 'Decompress' {
 
         BeforeAll {
             if ($env:CI) {
-                Mock Get-AppFilePath { $env:lessmsi }
+                Mock Get-AppFilePath { $env:SCOOP_LESSMSI_PATH }
             } elseif (!(installed lessmsi)) {
                 scoop install lessmsi
             }
@@ -148,7 +149,7 @@ Describe 'Decompression function' -Tag 'Scoop', 'Decompress' {
 
         BeforeAll {
             if ($env:CI) {
-                Mock Get-AppFilePath { $env:innounp }
+                Mock Get-AppFilePath { $env:SCOOP_INNOUNP_PATH }
             } elseif (!(installed innounp)) {
                 scoop install innounp
             }
diff --git a/test/bin/init.ps1 b/test/bin/init.ps1
index 5e709bc85d..c3125f9a71 100644
--- a/test/bin/init.ps1
+++ b/test/bin/init.ps1
@@ -1,33 +1,9 @@
 Write-Host "PowerShell: $($PSVersionTable.PSVersion)"
-(7z.exe | Select-String -Pattern '7-Zip').ToString()
+Write-Host (7z.exe | Select-String -Pattern '7-Zip').ToString()
 Write-Host 'Install dependencies ...'
 Install-Module -Repository PSGallery -Scope CurrentUser -Force -Name Pester -RequiredVersion 4.10.1 -SkipPublisherCheck
 Install-Module -Repository PSGallery -Scope CurrentUser -Force -Name PSScriptAnalyzer, BuildHelpers
 
-if ($env:CI_WINDOWS -eq $true) {
-    # Do not force maintainers to have this inside environment appveyor config
-    if (-not $env:SCOOP_HELPERS) {
-        $env:SCOOP_HELPERS = 'C:\projects\helpers'
-        [System.Environment]::SetEnvironmentVariable('SCOOP_HELPERS', $env:SCOOP_HELPERS, 'Machine')
-    }
-
-    if (!(Test-Path $env:SCOOP_HELPERS)) {
-        New-Item -ItemType Directory -Path $env:SCOOP_HELPERS
-    }
-    if (!(Test-Path "$env:SCOOP_HELPERS\lessmsi\lessmsi.exe")) {
-        Start-FileDownload 'https://github.com/activescott/lessmsi/releases/download/v1.10.0/lessmsi-v1.10.0.zip' -FileName "$env:SCOOP_HELPERS\lessmsi.zip"
-        & 7z.exe x "$env:SCOOP_HELPERS\lessmsi.zip" -o"$env:SCOOP_HELPERS\lessmsi" -y
-    }
-    if (!(Test-Path "$env:SCOOP_HELPERS\innounp\innounp.exe")) {
-        Start-FileDownload 'https://raw.githubusercontent.com/ScoopInstaller/Binary/master/innounp/innounp050.rar' -FileName "$env:SCOOP_HELPERS\innounp.rar"
-        & 7z.exe x "$env:SCOOP_HELPERS\innounp.rar" -o"$env:SCOOP_HELPERS\innounp" -y
-    }
-    if (!(Test-Path "$env:SCOOP_HELPERS\zstd\zstd.exe")) {
-        Start-FileDownload 'https://github.com/facebook/zstd/releases/download/v1.5.0/zstd-v1.5.0-win32.zip' -FileName "$env:SCOOP_HELPERS\zstd.zip"
-        & 7z.exe x "$env:SCOOP_HELPERS\zstd.zip" 'zstd-v1.5.0-win32' -o"$env:SCOOP_HELPERS\zstd" -y
-    }
-}
-
 if ($env:CI -eq $true) {
     Write-Host "Load 'BuildHelpers' environment variables ..."
     Set-BuildEnvironment -Force
diff --git a/test/bin/test.ps1 b/test/bin/test.ps1
index 51b7cc9ad0..71121f806f 100644
--- a/test/bin/test.ps1
+++ b/test/bin/test.ps1
@@ -11,9 +11,9 @@ $splat = @{
     PassThru = $true
 }
 
+$excludes = @()
 if ($env:CI -eq $true) {
     $resultsXml = "$PSScriptRoot/TestResults.xml"
-    $excludes = @()
 
     $splat += @{
         OutputFile   = $resultsXml
@@ -35,8 +35,7 @@ if ($env:CI -eq $true) {
         $excludes += 'Scoop'
     }
 
-    $changed_scripts = (Get-GitChangedFile -Include '*decompress.ps1' -Commit $commit)
-    if (!$changed_scripts) {
+    if (!($changed_scripts -like '*decompress.ps1')) {
         Write-Warning "Skipping tests and code linting for decompress.ps1 files because it didn't change"
         $excludes += 'Decompress'
     }
@@ -56,6 +55,30 @@ if ($env:CI -eq $true) {
         Write-Warning "Skipping tests and validation for manifest files because they didn't change"
         $excludes += 'Manifests'
     }
+
+    if ('Decompress' -notin $excludes) {
+        Write-Host 'Install decompress dependencies ...'
+
+        $env:SCOOP_HELPERS_PATH = 'C:\projects\helpers'
+        if (!(Test-Path $env:SCOOP_HELPERS_PATH)) {
+            New-Item -ItemType Directory -Path $env:SCOOP_HELPERS_PATH
+        }
+        if (!(Test-Path "$env:SCOOP_HELPERS_PATH\lessmsi\lessmsi.exe")) {
+            Start-FileDownload 'https://github.com/activescott/lessmsi/releases/download/v1.10.0/lessmsi-v1.10.0.zip' -FileName "$env:SCOOP_HELPERS_PATH\lessmsi.zip"
+            & 7z.exe x "$env:SCOOP_HELPERS_PATH\lessmsi.zip" -o"$env:SCOOP_HELPERS_PATH\lessmsi" -y
+            $env:SCOOP_LESSMSI_PATH = "$env:SCOOP_HELPERS_PATH\lessmsi\lessmsi.exe"
+        }
+        if (!(Test-Path "$env:SCOOP_HELPERS_PATH\innounp\innounp.exe")) {
+            Start-FileDownload 'https://raw.githubusercontent.com/ScoopInstaller/Binary/master/innounp/innounp050.rar' -FileName "$env:SCOOP_HELPERS_PATH\innounp.rar"
+            & 7z.exe x "$env:SCOOP_HELPERS_PATH\innounp.rar" -o"$env:SCOOP_HELPERS_PATH\innounp" -y
+            $env:SCOOP_INNOUNP_PATH = "$env:SCOOP_HELPERS_PATH\innounp\innounp.exe"
+        }
+        if (!(Test-Path "$env:SCOOP_HELPERS_PATH\zstd\zstd.exe")) {
+            Start-FileDownload 'https://github.com/facebook/zstd/releases/download/v1.5.1/zstd-v1.5.1-win32.zip' -FileName "$env:SCOOP_HELPERS_PATH\zstd.zip"
+            & 7z.exe x "$env:SCOOP_HELPERS_PATH\zstd.zip" -o"$env:SCOOP_HELPERS_PATH\zstd" -y
+            $env:SCOOP_ZSTD_PATH = "$env:SCOOP_HELPERS_PATH\zstd\zstd.exe"
+        }
+    }
 }
 
 if (!(Test-Path "$PSScriptRoot\..\..\bucket")) {