diff --git a/pester-extensions.psm1 b/pester-extensions.psm1
index 2531af4..82c40b3 100644
--- a/pester-extensions.psm1
+++ b/pester-extensions.psm1
@@ -4,51 +4,30 @@ Pester extension that allows to run command and validate exit code
 .EXAMPLE
 "python file.py" | Should -ReturnZeroExitCode
 #>
-
-function Get-CommandResult {
-    param (
-        [Parameter(Mandatory=$true)]
-        [string] $Command,
-        [switch] $Multiline
-    )
-    # Bash trick to suppress and show error output because some commands write to stderr (for example, "python --version")
-    if ($IsWindows) {
-        [string[]]$stdout = & $env:comspec /c "$Command 2>&1"
-    } else {
-        $stdout = & bash -c "$Command 2>&1"
-    }
-    $exitCode = $LASTEXITCODE
-    return @{
-        Output = If ($Multiline -eq $true) { $stdout } else { [string]$stdout }
-        ExitCode = $exitCode
-    }
-}
-
 function ShouldReturnZeroExitCode {
     Param(
-        [String] $ActualValue,
-        [switch] $Negate,
-        [string] $Because # This parameter is unused by we need it to match Pester asserts signature
+        [Parameter (Mandatory = $true)] [ValidateNotNullOrEmpty()]
+        [String]$ActualValue,
+        [switch]$Negate
     )
 
-    $result = Get-CommandResult $ActualValue
+    Write-Host "Run command '${ActualValue}'"
+    Invoke-Expression -Command $ActualValue | ForEach-Object { Write-Host $_ }
+    $actualExitCode = $LASTEXITCODE
 
-    [bool]$succeeded = $result.ExitCode -eq 0
+    [bool]$succeeded = $actualExitCode -eq 0
     if ($Negate) { $succeeded = -not $succeeded }
 
     if (-not $succeeded)
     {
-        $commandOutputIndent = " " * 4
-        $commandOutput = ($result.Output | ForEach-Object { "${commandOutputIndent}${_}" }) -join "`n"
-        $failureMessage = "Command '${ActualValue}' has finished with exit code ${actualExitCode}`n${commandOutput}"
+        $failureMessage = "Command '${ActualValue}' has finished with exit code ${actualExitCode}"
     }
 
-    return [PSCustomObject] @{
+    return New-Object PSObject -Property @{
         Succeeded      = $succeeded
         FailureMessage = $failureMessage
     }
 }
 
-if (Get-Command -Name Add-AssertionOperator -ErrorAction SilentlyContinue) {
-    Add-AssertionOperator -Name ReturnZeroExitCode -InternalName ShouldReturnZeroExitCode -Test ${function:ShouldReturnZeroExitCode}
-}
+Add-AssertionOperator -Name ReturnZeroExitCode `
+                    -Test  $function:ShouldReturnZeroExitCode
\ No newline at end of file