diff --git a/doc/100-General/10-Changelog.md b/doc/100-General/10-Changelog.md
index ac3ace1..6a7dac7 100644
--- a/doc/100-General/10-Changelog.md
+++ b/doc/100-General/10-Changelog.md
@@ -17,6 +17,10 @@ Released closed milestones can be found on [GitHub](https://github.com/Icinga/ic
 * [#403](https://github.com/Icinga/icinga-powershell-framework/pull/403) Fixes memory leak on newly EventLog reader for CLI event stream
 * [#407](https://github.com/Icinga/icinga-powershell-framework/pull/407) Removes unnecessary module import inside `Invoke-IcingaNamespaceCmdlets`
 
+### Enhancements
+
+* [#388](https://github.com/Icinga/icinga-powershell-framework/issues/388) Improves performance for testing if `Add-Type` functions have been added, by adding an internal test for newly introduced environment variables within a PowerShell session
+
 ## 1.7.1 (2021-11-11)
 
 [Issue and PRs](https://github.com/Icinga/icinga-powershell-framework/milestone/22?closed=1)
diff --git a/lib/core/framework/Get-IcingaPrivateEnvironmentVariable.psm1 b/lib/core/framework/Get-IcingaPrivateEnvironmentVariable.psm1
new file mode 100644
index 0000000..4bce893
--- /dev/null
+++ b/lib/core/framework/Get-IcingaPrivateEnvironmentVariable.psm1
@@ -0,0 +1,33 @@
+<#
+.SYNOPSIS
+    Reads a private environment variable from Icinga for Windows
+    of the current PowerShell session
+.DESCRIPTION
+    Reads a private environment variable from Icinga for Windows
+    of the current PowerShell session
+.PARAMETER Name
+    The name of the variable to load the content from
+.EXAMPLE
+    Get-IcingaPrivateEnvironmentVariable -Name 'AddTypeFunctions';
+.NOTES
+General notes
+#>
+function Get-IcingaPrivateEnvironmentVariable()
+{
+    param (
+        [string]$Name
+    );
+
+    if ([string]::IsNullOrEmpty($Name)) {
+        return $null;
+    }
+
+    # Setup the environments in case not present already
+    New-IcingaEnvironmentVariable;
+
+    if ($global:Icinga.Private.ContainsKey($Name) -eq $FALSE) {
+        return $null;
+    }
+
+    return $global:Icinga.Private[$Name];
+}
diff --git a/lib/core/framework/New-IcingaCheckSchedulerEnvironment.psm1 b/lib/core/framework/New-IcingaCheckSchedulerEnvironment.psm1
index 7f36751..03007ab 100644
--- a/lib/core/framework/New-IcingaCheckSchedulerEnvironment.psm1
+++ b/lib/core/framework/New-IcingaCheckSchedulerEnvironment.psm1
@@ -44,17 +44,5 @@ function New-IcingaCheckSchedulerEnvironment()
         $IcingaDaemonData.IcingaThreadContent.Add('Scheduler', @{ });
     }
 
-    if ($null -eq $global:Icinga) {
-        $global:Icinga = @{ };
-    }
-
-    if ($global:Icinga.ContainsKey('CheckResults') -eq $FALSE) {
-        $global:Icinga.Add('CheckResults', @());
-    }
-    if ($global:Icinga.ContainsKey('PerfData') -eq $FALSE) {
-        $global:Icinga.Add('PerfData', @());
-    }
-    if ($global:Icinga.ContainsKey('CheckData') -eq $FALSE) {
-        $global:Icinga.Add('CheckData', @{ });
-    }
+    New-IcingaEnvironmentVariable;
 }
diff --git a/lib/core/framework/New-IcingaEnvironmentVariable.psm1 b/lib/core/framework/New-IcingaEnvironmentVariable.psm1
new file mode 100644
index 0000000..7da7989
--- /dev/null
+++ b/lib/core/framework/New-IcingaEnvironmentVariable.psm1
@@ -0,0 +1,37 @@
+<#
+.SYNOPSIS
+    Creates all environment variables for Icinga for Windows for the
+    PowerShell session
+.DESCRIPTION
+    Creates all environment variables for Icinga for Windows for the
+    PowerShell session
+.EXAMPLE
+    New-IcingaEnvironmentVariable;
+#>
+
+function New-IcingaEnvironmentVariable()
+{
+    if ($null -eq $global:Icinga) {
+        $global:Icinga = @{ };
+    }
+
+    # Session specific configuration for this shell
+    if ($global:Icinga.ContainsKey('Private') -eq $FALSE) {
+        $global:Icinga.Add('Private', @{ });
+    }
+
+    # Shared configuration for all threads
+    if ($global:Icinga.ContainsKey('Public') -eq $FALSE) {
+        $global:Icinga.Add('Public', [hashtable]::Synchronized(@{ }));
+    }
+
+    if ($global:Icinga.ContainsKey('CheckResults') -eq $FALSE) {
+        $global:Icinga.Add('CheckResults', @());
+    }
+    if ($global:Icinga.ContainsKey('PerfData') -eq $FALSE) {
+        $global:Icinga.Add('PerfData', @());
+    }
+    if ($global:Icinga.ContainsKey('CheckData') -eq $FALSE) {
+        $global:Icinga.Add('CheckData', @{ });
+    }
+}
diff --git a/lib/core/framework/Set-IcingaPrivateEnvironmentVariable.psm1 b/lib/core/framework/Set-IcingaPrivateEnvironmentVariable.psm1
new file mode 100644
index 0000000..55ee4bd
--- /dev/null
+++ b/lib/core/framework/Set-IcingaPrivateEnvironmentVariable.psm1
@@ -0,0 +1,36 @@
+<#
+.SYNOPSIS
+    Sets a private variable for the Icinga for Windows environment
+    to use within the current PowerShell Session
+.DESCRIPTION
+    Sets a private variable for the Icinga for Windows environment
+    to use within the current PowerShell Session
+.PARAMETER Name
+    The name of the variable
+.PARAMETER Value
+    The value the variable will be assigned with
+.EXAMPLE
+    Set-IcingaPrivateEnvironmentVariable -Name 'AddTypeFunctions' -Value @{ 'IcingaDiskAttributes', $TRUE };
+#>
+
+function Set-IcingaPrivateEnvironmentVariable()
+{
+    param (
+        [string]$Name,
+        $Value
+    );
+
+    if ([string]::IsNullOrEmpty($Name)) {
+        return;
+    }
+
+    # Setup the environments in case not present already
+    New-IcingaEnvironmentVariable;
+
+    if ($global:Icinga.Private.ContainsKey($Name) -eq $FALSE) {
+        $global:Icinga.Private.Add($Name, $Value);
+        return;
+    }
+
+    $global:Icinga.Private[$Name] = $Value;
+}
diff --git a/lib/core/tools/Test-IcingaAddTypeExist.psm1 b/lib/core/tools/Test-IcingaAddTypeExist.psm1
index 0c5fa7e..e1a6bb7 100644
--- a/lib/core/tools/Test-IcingaAddTypeExist.psm1
+++ b/lib/core/tools/Test-IcingaAddTypeExist.psm1
@@ -1,3 +1,15 @@
+<#
+.SYNOPSIS
+    Tests if a Add-Type function is already installed inside the current
+    PowerShell session
+.DESCRIPTION
+    Tests if a Add-Type function is already installed inside the current
+    PowerShell session
+.PARAMETER Type
+    The name of the function being added
+.EXAMPLE
+    Test-IcingaAddTypeExis -Type 'IcingaDiskAttributes';
+#>
 function Test-IcingaAddTypeExist()
 {
     param (
@@ -8,8 +20,22 @@ function Test-IcingaAddTypeExist()
         return $FALSE;
     }
 
+    [hashtable]$LoadedTypes = Get-IcingaPrivateEnvironmentVariable -Name 'AddTypeFunctions';
+
+    if ($null -eq $LoadedTypes) {
+        $LoadedTypes = @{ };
+    }
+
+    if ($LoadedTypes.ContainsKey($Type)) {
+        return $TRUE;
+    }
+
     foreach ($entry in [System.AppDomain]::CurrentDomain.GetAssemblies()) {
         if ($entry.GetTypes() -Match $Type) {
+            $LoadedTypes.Add($Type, $TRUE);
+
+            Set-IcingaPrivateEnvironmentVariable -Name 'AddTypeFunctions' -Value $LoadedTypes;
+
             return $TRUE;
         }
     }