diff --git a/windows/security/threat-protection/windows-defender-exploit-guard/attack-surface-reduction-exploit-guard.md b/windows/security/threat-protection/windows-defender-exploit-guard/attack-surface-reduction-exploit-guard.md
index d90ef31aa2..125ff2e581 100644
--- a/windows/security/threat-protection/windows-defender-exploit-guard/attack-surface-reduction-exploit-guard.md
+++ b/windows/security/threat-protection/windows-defender-exploit-guard/attack-surface-reduction-exploit-guard.md
@@ -11,7 +11,7 @@ ms.pagetype: security
 ms.localizationpriority: medium
 author: andreabichsel
 ms.author: v-anbic
-ms.date: 11/27/2018
+ms.date: 11/29/2018
 ---
 
 # Reduce attack surfaces with attack surface reduction rules 
@@ -31,6 +31,8 @@ Attack surface reduction rules help prevent actions and apps that are typically
 
 When an attack surface reduction rule is triggered, a notification displays from the Action Center on the user's computer. You can [customize the notification](customize-attack-surface-reduction.md#customize-the-notification) with your company details and contact information.
 
+Attack surface reduction is supported on Windows 10, version 1709 and later and Windows Server 2019.
+
 ## Requirements
 
 Attack surface reduction rules are a feature of Windows Defender ATP and require Windows 10 Enterprise E5 and [Windows Defender AV real-time protection](../windows-defender-antivirus/configure-real-time-protection-windows-defender-antivirus.md).