diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4785146d1..adadf58b0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Updated PULL_REQUEST_TEMPLATE.md to match DSC standard
 - SPFarm
   - Added possibility to set application credential key.
+- SPTrustedSecurityTokenIssuer
+  - Fixed RegisteredIssuerNameRealm not applied if specified.
 
 ### Changed
 
diff --git a/SharePointDsc/DSCResources/MSFT_SPTrustedSecurityTokenIssuer/MSFT_SPTrustedSecurityTokenIssuer.psm1 b/SharePointDsc/DSCResources/MSFT_SPTrustedSecurityTokenIssuer/MSFT_SPTrustedSecurityTokenIssuer.psm1
index 881f0e2ae..468b4d65d 100644
--- a/SharePointDsc/DSCResources/MSFT_SPTrustedSecurityTokenIssuer/MSFT_SPTrustedSecurityTokenIssuer.psm1
+++ b/SharePointDsc/DSCResources/MSFT_SPTrustedSecurityTokenIssuer/MSFT_SPTrustedSecurityTokenIssuer.psm1
@@ -300,6 +300,11 @@ function Set-TargetResource
                     Write-Verbose -Message "RegisteredIssuerNameRealm is not specified, use Get-SPAuthenticationRealm instead."
                     $registeredIssuerNameRealm = Get-SPAuthenticationRealm
                 }
+                else
+                {
+                    $registeredIssuerNameRealm = $params.RegisteredIssuerNameRealm
+                }
+
                 $registeredIssuerName = "$($params.RegisteredIssuerNameIdentifier)@$registeredIssuerNameRealm"
 
                 $runParams.Add("RegisteredIssuerName", $registeredIssuerName)