diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9166c3a..04672e0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,12 @@
 
+# 1.1.0
+
+Added `Test-CTypeDataMember` and `Add-CTypeData` functions for testing if a type has any defined custom type data and
+adding custom type data, respectively. Defining type data with .ps1xml files can result in errors importing the same
+module multiple times: PowerShell complains that the type data is already defined. Using `Add-CTypeData` prevents these
+this error as it only adds members that don't already exist.
+
+
 # 1.0.0
 
 ## Upgrade Instructions
@@ -23,7 +31,7 @@ a string, and pass that string to the `Command` parameter. This will base64 enco
 PowerShell's -EncodedCommand property.
 * The `Invoke-CPowerShell` function no longer has `FilePath`, `OutputFormat`, `ExecutionPolicy`, `NonInteractive`, 
 or `Runtime` parameters. Instead, pass these as arguments to the `ArgumentList` parameter, e.g. 
-`-ArgumentList @('-NonInteractive', '-ExecutionPolicy', 'Bypasss'). You are now responsible for passing all PowerShell
+`-ArgumentList @('-NonInteractive', '-ExecutionPolicy', 'Bypasss')`. You are now responsible for passing all PowerShell
 arguments via the `ArgumentList` parameter.
 * The `Invoke-CPowerShell` function no longer supports running PowerShell 2 under .NET 4.
 * Remove the `-Encode` switch. `Invoke-CPowerShell` now always base64 encodes the value of the `Command` parameter.
diff --git a/Carbon.Core/Carbon.Core.psd1 b/Carbon.Core/Carbon.Core.psd1
index ae907e4..40bc607 100644
--- a/Carbon.Core/Carbon.Core.psd1
+++ b/Carbon.Core/Carbon.Core.psd1
@@ -18,7 +18,7 @@
     RootModule = 'Carbon.Core.psm1'
 
     # Version number of this module.
-    ModuleVersion = '1.0.0'
+    ModuleVersion = '1.1.0'
 
     # ID used to uniquely identify this module
     GUID = '20DA9F42-23C4-4917-8597-DCFD7EE4AD00'
@@ -76,12 +76,14 @@
 
     # Functions to export from this module. Only list public function here.
     FunctionsToExport = @(
+        'Add-CTypeData',
         'ConvertTo-CBase64',
         'Get-CPowerShellPath',
         'Invoke-CPowerShell',
         'Start-CPowerShellProcess',
         'Test-COperatingSystem',
-        'Test-CPowerShell'
+        'Test-CPowerShell',
+        'Test-CTypeDataMember'
     )
 
     # Cmdlets to export from this module. By default, you get a script module, so there are no cmdlets.
diff --git a/Carbon.Core/Functions/Add-CTypeData.ps1 b/Carbon.Core/Functions/Add-CTypeData.ps1
new file mode 100644
index 0000000..55ffdbe
--- /dev/null
+++ b/Carbon.Core/Functions/Add-CTypeData.ps1
@@ -0,0 +1,115 @@
+function Add-CTypeData
+{
+    <#
+    .SYNOPSIS
+    Adds type data to a type only if the type data doesn't already exist.
+
+    .DESCRIPTION
+    The `Add-CTypeData` function uses PowerShell's `Update-TypeData` cmdlet to add type data to a type, but only if the
+    given type data doesn't already exist. Pass the type to the `Type` parameter or the type name to the `TypeName`
+    parameter, the new type data member type to the `MemberType` parameter (e.g. `AliasProperty`, `NoteProperty`, 
+    `ScriptProperty`, or `ScriptMethod`), the member name to the `MemberName` parameter, and the member's
+    value/implementation to the `Value` parameter.
+
+    Note that the `Type` parameter should be the bare name of the type, e.g. `Diagnostics.Process`, *without* square
+    brackets.
+
+    If the type already has an equivalent member with the name given by the `MemberName` parameter, nothing happens, and
+    the function returns.
+
+    .EXAMPLE
+    Add-CTypeData -Type Diagnostics.Process -MemberType ScriptProperty  -MemberName 'ParentID' -Value $scriptBlock
+
+    Demonstrates how to create a script property on a type. In this example, the `System.Diagnostics.Process` type will
+    be given a `ParentID` property that runs the code in the script block in the `$scriptBlock` variable.
+
+    .EXAMPLE
+    Add-CTypeData -Type Diagnostics.Process -MemberType ScriptMethod  -MemberName 'GetParentID()' -Value $scriptBlock
+
+    Demonstrates how to create a script method on a type. In this example, the `System.Diagnostics.Process` type will
+    be given a `GetParentID()` method that runs the code in the script block in the `$scriptBlock` variable.
+
+    .EXAMPLE
+    Add-CTypeData -Type Diagnostics.Process -MemberType AliasProperty  -MemberName 'ProcessId' -Value 'Id'
+
+    Demonstrates how to create an alias script property on a type. In this example, the `System.Diagnostics.Process`
+    type will be given a `ProcessId` property that is an alias to the 'Id' property.
+
+    .EXAMPLE
+    Add-CTypeData -Type Diagnostics.Process -MemberType NoteProperty  -MemberName 'ParentID' -Value $parentPid
+
+    Demonstrates how to create a ntoe property on a type. In this example, the `System.Diagnostics.Process` type will
+    be given a `ParentID` property that returns the value in the `$parentPid` variable.
+    #>
+    [CmdletBinding()]
+    param(
+        # The type on which to add the type data. This should be the bare type name, e.g. Diagnostics.Process, *not*
+        # the type surrounded by square brackets, e.g. `[Diagnostics.Process]`.
+        [Parameter(Mandatory, ParameterSetName='ByType')]
+        [Type] $Type,
+
+        # The name of the type on which to add the type data.
+        [Parameter(Mandatory, ParameterSetName='ByTypeName')]
+        [String] $TypeName,
+
+        # The member type of the new type data. Only `AliasProperty`, `NoteProperty`, `ScriptProperty`, `ScriptMethod`
+        # are supported.
+        [Parameter(Mandatory)]
+        [ValidateSet('AliasProperty', 'NoteProperty', 'ScriptProperty', 'ScriptMethod')]
+        [Management.Automation.PSMemberTypes] $MemberType,
+
+        # The type data's member name.
+        [Parameter(Mandatory)]
+        [String] $MemberName,
+
+        # The value for the member. If `MemberName` is:
+        #
+        # * `AliasProperty`, this should be the name of the target property.
+        # * `NoteProperty`, the literal value of the property.
+        # * `ScriptProperty`, a script block that return's the property value.
+        # * `ScriptMethod`, a script block that implements the method logic.
+        [Parameter(Mandatory)]
+        [Object] $Value
+    )
+
+    Set-StrictMode -Version 'Latest'
+    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState
+
+    $memberTypeMsg = '{0,-14}' -f $MemberType
+
+    if( -not $TypeName )
+    {
+        $TypeName = $Type.FullName
+    }
+
+    if( $Type )
+    {
+        if( $MemberType -like '*Property' )
+        {
+            if( ($Type.GetProperties() | Where-Object Name -EQ $MemberName) )
+            {
+                Write-Debug ("Type        $($memberTypeMsg)  [$($TypeName)]  $($MemberName)")
+                return
+            }
+        }
+        elseif( $MemberType -like '*Method')
+        {
+            if( ($Type.GetMethods() | Where-Object Name -EQ $MemberName) )
+            {
+                Write-Debug ("Type        $($memberTypeMsg)  [$($TypeName)]  $($MemberName)")
+                return
+            }
+        }
+    }
+
+    $typeData = Get-TypeData -TypeName $TypeName
+    if( $typeData -and $typeData.Members.ContainsKey($MemberName) )
+    {
+        Write-Debug ("TypeData    $($memberTypeMsg)  [$($TypeName)]  $($MemberName)")
+        return
+    }
+
+    Write-Debug ("TypeData  + $($memberTypeMsg)  [$($TypeName)]  $($MemberName)")
+    Update-TypeData -TypeName $TypeName -MemberType $MemberType -MemberName $MemberName -Value $Value
+}
+
diff --git a/Carbon.Core/Functions/Test-CTypeDataMember.ps1 b/Carbon.Core/Functions/Test-CTypeDataMember.ps1
new file mode 100644
index 0000000..0bf6332
--- /dev/null
+++ b/Carbon.Core/Functions/Test-CTypeDataMember.ps1
@@ -0,0 +1,44 @@
+
+function Test-CTypeDataMember
+{
+    <#
+    .SYNOPSIS
+    Tests if a type has an extended type member defined.
+
+    .DESCRIPTION
+    `Test-CTypeDataMember` tests if a type has an extended type member defined. If the type isn't found, you'll get an
+    error.
+
+    Returns `$true` if the type is found and the member is defined. Otherwise, returns `$false`.
+
+    .EXAMPLE
+    Test-CTypeDataMember -TypeName 'Microsoft.Web.Administration.Site' -MemberName 'PhysicalPath'
+
+    Tests if the `Microsoft.Web.Administration.Site` type has a `PhysicalPath` extended type member defined.
+    #>
+    [CmdletBinding()]
+    [OutputType([bool])]
+    param(
+        # The type name to check.
+        [Parameter(Mandatory)]
+        [String] $TypeName,
+
+        # The name of the member to check.
+        [Parameter(Mandatory)]
+        [String] $MemberName
+    )
+
+    Set-StrictMode -Version 'Latest'
+    Use-CallerPreference -Cmdlet $PSCmdlet -Session $ExecutionContext.SessionState
+
+    $typeData = Get-TypeData -TypeName $TypeName
+    if( -not $typeData )
+    {
+        # The type isn't defined or there is no extended type data on it.
+        return $false
+    }
+
+    return $typeData.Members.ContainsKey( $MemberName )
+}
+
+