diff --git a/Functions/Assertions/Should.Tests.ps1 b/Functions/Assertions/Should.Tests.ps1
index 89b36bf84..e72fd0235 100644
--- a/Functions/Assertions/Should.Tests.ps1
+++ b/Functions/Assertions/Should.Tests.ps1
@@ -109,7 +109,7 @@ InModuleScope Pester {
         It "ensures all assertion functions provide failure messages" {
             $assertionFunctions = @("PesterBe", "PesterThrow", "PesterBeNullOrEmpty", "PesterExist",
                 "PesterMatch", "PesterContain")
-            $assertionFunctions | % {
+            $assertionFunctions | ForEach {
                 "function:$($_)FailureMessage" | Should Exist
                 "function:Not$($_)FailureMessage" | Should Exist
                 "function:$($_)FailureMessage" | Should -Exist
@@ -138,8 +138,8 @@ InModuleScope Pester {
         <#
         It 'All failure message functions are present' {
             $assertionFunctions = Get-Command -CommandType Function -Module Pester |
-                                  Select-Object -ExpandProperty Name |
-                                  Where-Object { $_ -like 'Pester*' -and $_ -notlike '*FailureMessage' }
+                                  Select -ExpandProperty Name |
+                                  Where { $_ -like 'Pester*' -and $_ -notlike '*FailureMessage' }
 
             $missingFunctions = @(
                 foreach ($assertionFunction in $assertionFunctions)
diff --git a/Functions/GherkinHook.ps1 b/Functions/GherkinHook.ps1
index d81915032..ff31ab779 100644
--- a/Functions/GherkinHook.ps1
+++ b/Functions/GherkinHook.ps1
@@ -16,7 +16,7 @@ function BeforeEachFeature {
     param(
         # Optional tags. If set, this hook only runs for features with matching tags
         [Parameter(Mandatory=$True, Position=0, ParameterSetName="Tags")]
-        [String[]]$Tags = @(),
+        [String[]]$Tags,
 
         # The ScriptBlock to run for the hook
         [Parameter(Mandatory=$True, Position=1, ParameterSetName="Tags")]
@@ -45,7 +45,7 @@ function AfterEachFeature {
     param(
         # Optional tags. If set, this hook only runs for features with matching tags
         [Parameter(Mandatory=$True, Position=0, ParameterSetName="Tags")]
-        [String[]]$Tags = @(),
+        [String[]]$Tags,
 
         # The ScriptBlock to run for the hook
         [Parameter(Mandatory=$True, Position=1, ParameterSetName="Tags")]
@@ -76,7 +76,7 @@ function BeforeEachScenario {
     param(
         # Optional tags. If set, this hook only runs for features with matching tags
         [Parameter(Mandatory=$True, Position=0, ParameterSetName="Tags")]
-        [String[]]$Tags = @(),
+        [String[]]$Tags,
 
         # The ScriptBlock to run for the hook
         [Parameter(Mandatory=$True, Position=1, ParameterSetName="Tags")]
@@ -105,7 +105,7 @@ function AfterEachScenario {
     param(
         # Optional tags. If set, this hook only runs for features with matching tags
         [Parameter(Mandatory=$True, Position=0, ParameterSetName="Tags")]
-        [String[]]$Tags = @(),
+        [String[]]$Tags,
 
         # The ScriptBlock to run for the hook
         [Parameter(Mandatory=$True, Position=1, ParameterSetName="Tags")]
diff --git a/Functions/Mock.Tests.ps1 b/Functions/Mock.Tests.ps1
index d4474e4b2..4ddfec682 100644
--- a/Functions/Mock.Tests.ps1
+++ b/Functions/Mock.Tests.ps1
@@ -257,7 +257,7 @@ Describe "When calling Mock on existing cmdlet to handle pipelined input" {
     }
 
     $result = ''
-    "a", "b" | Get-ChildItem | % { $result += $_ }
+    "a", "b" | Get-ChildItem | ForEach { $result += $_ }
 
     It "Should process the pipeline in the mocked script" {
         $result | Should Be "AABB"
@@ -1302,7 +1302,7 @@ Describe 'Parameter Filters and Common Parameters' {
 Describe "Mocking Get-ItemProperty" {
     Mock Get-ItemProperty { New-Object -typename psobject -property @{ Name = "fakeName" } }
     It "Does not fail with NotImplementedException" {
-        Get-ItemProperty -Path "HKLM:\Software\Key\" -Name "Property" | Select -ExpandProperty Name | Should Be fakeName
+        Get-ItemProperty -Path "HKLM:\Software\Key\" -Name "Property" | Select-Object -ExpandProperty Name | Should Be fakeName
     }
 }
 
@@ -1397,7 +1397,7 @@ Describe 'Mocking a function taking input from pipeline' {
     context 'when calling original function with an array' {
         $result = @(1,2) | PipelineInputFunction
         it 'Returns actual implementation' {
-            $result[0].keys | % {
+            $result[0].keys | ForEach {
                 $result[0][$_] | Should Be $noMockArrayResult[0][$_]
                 $result[1][$_] | Should Be $noMockArrayResult[1][$_]
             }
@@ -1407,7 +1407,7 @@ Describe 'Mocking a function taking input from pipeline' {
     context 'when calling original function with an int' {
         $result = 1 | PipelineInputFunction
         it 'Returns actual implementation' {
-            $result.keys | % {
+            $result.keys | ForEach {
                 $result[$_] | Should Be $noMockIntResult[$_]
             }
         }
@@ -1416,7 +1416,7 @@ Describe 'Mocking a function taking input from pipeline' {
     context 'when calling original function with a string' {
         $result = '1' | PipelineInputFunction
         it 'Returns actual implementation' {
-            $result.keys | % {
+            $result.keys | ForEach {
                 $result[$_] | Should Be $noMockStringResult[$_]
             }
         }
@@ -1425,7 +1425,7 @@ Describe 'Mocking a function taking input from pipeline' {
     context 'when calling original function and pipeline is bound by property name' {
         $result = $psobj | PipelineInputFunction -PipeStr 'val'
         it 'Returns actual implementation' {
-            $result.keys | % {
+            $result.keys | ForEach {
                 $result[$_] | Should Be $noMockResultByProperty[$_]
             }
         }
@@ -1448,7 +1448,7 @@ Describe 'Mocking a function taking input from pipeline' {
     context 'when calling original function and pipeline is bound by property name with array values' {
         $result = $psArrayobj | PipelineInputFunction -PipeStr 'val'
         it 'Returns actual implementation' {
-            $result.keys | % {
+            $result.keys | ForEach {
                 $result[$_] | Should Be $noMockArrayResultByProperty[$_]
             }
         }
diff --git a/Functions/New-Fixture.Tests.ps1 b/Functions/New-Fixture.Tests.ps1
index bd3978361..63c6acde6 100644
--- a/Functions/New-Fixture.Tests.ps1
+++ b/Functions/New-Fixture.Tests.ps1
@@ -10,9 +10,9 @@ Describe "New-Fixture" {
             $name = "Test-Fixture"
             $path = "TestDrive:\"
 
-            pushd  $path
+            Push-Location -Path $path
             New-Fixture -Name $name | Out-Null
-            popd
+            Pop-Location
 
             Join-Path -Path $path -ChildPath "$name.ps1" | Should Exist
             Join-Path -Path $path -ChildPath "$name.Tests.ps1" | Should Exist
@@ -40,9 +40,9 @@ Describe "New-Fixture" {
             $name = "Relative1-Fixture"
             $path = "TestDrive:\"
 
-            pushd  $path
+            Push-Location -Path $path
             New-Fixture -Name $name -Path relative | Out-Null
-            popd
+            Pop-Location
 
             Join-Path -Path "$path\relative" -ChildPath "$name.ps1" | Should Exist
             Join-Path -Path "$path\relative" -ChildPath "$name.Tests.ps1" | Should Exist
@@ -51,9 +51,9 @@ Describe "New-Fixture" {
             $name = "Relative2-Fixture"
             $path = "TestDrive:\"
 
-            pushd  $path
+            Push-Location -Path $path
             New-Fixture -Name $name -Path . | Out-Null
-            popd
+            Pop-Location
 
             Join-Path -Path "$path" -ChildPath "$name.ps1" | Should Exist
             Join-Path -Path "$path" -ChildPath "$name.Tests.ps1" | Should Exist
@@ -62,9 +62,9 @@ Describe "New-Fixture" {
             $name = "Relative3-Fixture"
             $path = "TestDrive:\"
 
-            pushd  $path
-            New-Fixture -Name $name -Path (pwd) | Out-Null
-            popd
+            Push-Location -Path $path
+            New-Fixture -Name $name -Path (Get-Location) | Out-Null
+            Pop-Location
 
             Join-Path -Path "$path" -ChildPath "$name.ps1" | Should Exist
             Join-Path -Path "$path" -ChildPath "$name.Tests.ps1" | Should Exist
diff --git a/Functions/Output.ps1 b/Functions/Output.ps1
index e0a3e4d6c..435adea0a 100644
--- a/Functions/Output.ps1
+++ b/Functions/Output.ps1
@@ -99,7 +99,7 @@ function Write-Describe {
         & $SafeCommands['Write-Host'] "${margin}${Text}" -ForegroundColor $ReportTheme.Describe
         # If the feature has a longer description, write that too
         if($Describe.PSObject.Properties['Description'] -and $Describe.Description) {
-            $Describe.Description -split '\n' | % {
+            $Describe.Description -split '\n' | ForEach {
                 & $SafeCommands['Write-Host'] ($ReportStrings.Margin * ($pester.IndentLevel + 1)) $_ -ForegroundColor $ReportTheme.DescribeDetail
             }
         }
@@ -123,7 +123,7 @@ function Write-Context {
         & $SafeCommands['Write-Host'] ($ReportStrings.Margin + $Text) -ForegroundColor $ReportTheme.Context
         # If the scenario has a longer description, write that too
         if($Context.PSObject.Properties['Description'] -and $Context.Description) {
-            $Context.Description -split '\n' | % {
+            $Context.Description -split '\n' | ForEach {
                 & $SafeCommands['Write-Host'] (" " * $ReportStrings.Context.Length) $_ -ForegroundColor $ReportTheme.ContextDetail
             }
         }
diff --git a/Functions/TestResults.Tests.ps1 b/Functions/TestResults.Tests.ps1
index 9086741da..91b63e88b 100644
--- a/Functions/TestResults.Tests.ps1
+++ b/Functions/TestResults.Tests.ps1
@@ -271,22 +271,22 @@ InModuleScope Pester {
 
     Describe "GetFullPath" {
         It "Resolves non existing path correctly" {
-            pushd TestDrive:\
+            Push-Location -Path TestDrive:\
             $p = GetFullPath notexistingfile.txt
-            popd
+            Pop-Location
             $p | Should Be (Join-Path $TestDrive notexistingfile.txt)
         }
 
         It "Resolves existing path correctly" {
-            pushd TestDrive:\
+            Push-Location -Path TestDrive:\
             New-Item -ItemType File -Name existingfile.txt
             $p = GetFullPath existingfile.txt
-            popd
+            Pop-Location
             $p | Should Be (Join-Path $TestDrive existingfile.txt)
         }
 
         It "Resolves full path correctly" {
-            $powershellPath = Get-Command 'powershell' | select -ExpandProperty 'Definition'
+            $powershellPath = Get-Command 'powershell' | Select -ExpandProperty 'Definition'
             $powershellPath | Should -Not -BeNullOrEmpty
 
             GetFullPath $powershellPath | Should Be $powershellPath
diff --git a/Functions/TestsRunningInCleanRunspace.Tests.ps1 b/Functions/TestsRunningInCleanRunspace.Tests.ps1
index db7299f5b..4db531886 100644
--- a/Functions/TestsRunningInCleanRunspace.Tests.ps1
+++ b/Functions/TestsRunningInCleanRunspace.Tests.ps1
@@ -27,7 +27,7 @@
     #TODO: how should this handle errors?
     #$job.Error | foreach { throw $_.Exception  }
     $job.Output
-    $job.ChildJobs| foreach {
+    $job.ChildJobs | ForEach {
         $childJob = $_
         #$childJob.Error | foreach { throw $_.Exception }
         $childJob.Output
diff --git a/Pester.Tests.ps1 b/Pester.Tests.ps1
index 8f2de962d..330003d35 100644
--- a/Pester.Tests.ps1
+++ b/Pester.Tests.ps1
@@ -88,7 +88,7 @@ if ($PSVersionTable.PSVersion.Major -ge 3)
             $path = $ExecutionContext.SessionState.Module.ModuleBase
             $filesToCheck = Get-ChildItem -Path $path -Recurse -Include *.ps1,*.psm1 -Exclude *.Tests.ps1
             $callsToSafeCommands = @(
-                foreach ($file in $files)
+                foreach ($file in $filesToCheck)
                 {
                     $tokens = $parseErrors = $null
                     $ast = [System.Management.Automation.Language.Parser]::ParseFile($file.FullName, [ref] $tokens, [ref] $parseErrors)
@@ -106,7 +106,11 @@ if ($PSVersionTable.PSVersion.Major -ge 3)
 
             $uniqueSafeCommands = $callsToSafeCommands | ForEach-Object { $_.CommandElements[0].Index.Value } | Select-Object -Unique
 
-            $missingSafeCommands = $uniqueSafeCommands | Where-Object { -not $script:SafeCommands.ContainsKey($_) }
+            $missingSafeCommands = $uniqueSafeCommands | Where { -not $script:SafeCommands.ContainsKey($_) }
+
+            # These commands are conditionally added to the safeCommands table due to Nano / Core versus PSv2 compatibility; one will always
+            # be missing, and can be ignored.
+            $missingSafeCommands = $missingSafeCommands | Where { @('Get-WmiObject', 'Get-CimInstance') -notcontains $_ }
 
             It 'The SafeCommands table contains all commands that are called from the module' {
                 $missingSafeCommands | Should Be $null
diff --git a/Pester.psm1 b/Pester.psm1
index 63b190db2..f3f482ec6 100644
--- a/Pester.psm1
+++ b/Pester.psm1
@@ -218,7 +218,7 @@ function Add-AssertionOperator
 
     $script:AssertionOperators[$Name] = $entry
 
-    foreach ($string in $Alias | where { -not (Test-NullOrWhiteSpace $_)})
+    foreach ($string in $Alias | Where { -not (Test-NullOrWhiteSpace $_)})
     {
         Assert-ValidAssertionAlias -Alias $string
         $script:AssertionAliases[$string] = $Name
@@ -233,7 +233,7 @@ function Assert-AssertionOperatorNameIsUnique
         [string[]] $Name
     )
 
-    foreach ($string in $name | where { -not (Test-NullOrWhiteSpace $_)})
+    foreach ($string in $name | Where { -not (Test-NullOrWhiteSpace $_)})
     {
         Assert-ValidAssertionName -Name $string
 
@@ -342,8 +342,6 @@ function Get-AssertionDynamicParams
 }
 
 $Script:PesterRoot = & $SafeCommands['Split-Path'] -Path $MyInvocation.MyCommand.Path
-$moduleRoot = & $script:SafeCommands['Split-Path'] -Path $MyInvocation.MyCommand.Path
-
 "$PesterRoot\Functions\*.ps1", "$PesterRoot\Functions\Assertions\*.ps1" |
 & $script:SafeCommands['Resolve-Path'] |
 & $script:SafeCommands['Where-Object'] { -not ($_.ProviderPath.ToLower().Contains(".tests.")) } |
diff --git a/build.psake.ps1 b/build.psake.ps1
index d6fae2a43..3f99faf49 100644
--- a/build.psake.ps1
+++ b/build.psake.ps1
@@ -23,8 +23,8 @@ Task Version-Module{
     $v = git.exe describe --abbrev=0 --tags
     $changeset=(git.exe log -1 $($v + '..') --pretty=format:%H)
     (Get-Content "$baseDir\Pester.psm1") `
-      | % {$_ -replace "\`$version\`$", "$version" } `
-      | % {$_ -replace "\`$sha\`$", "$changeset" } `
+      | Where {$_ -replace "\`$version\`$", "$version" } `
+      | Where {$_ -replace "\`$sha\`$", "$changeset" } `
       | Set-Content "$baseDir\Pester.psm1"
 }