diff --git a/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp b/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
index eee16185031a6..ce663a800fa46 100644
--- a/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
+++ b/security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
@@ -277,6 +277,9 @@ static void AddDeveloperRepoDirToPolicy(sandbox::TargetPolicy* aPolicy) {
 #undef WSTRING
 
 static void EnsureAppLockerAccess(sandbox::TargetPolicy* aPolicy) {
+  if (!IsWin7OrLater()) {
+    return;
+  }
   if (aPolicy->GetLockdownTokenLevel() < sandbox::USER_LIMITED) {
     // The following rules are to allow DLLs to be loaded when the token level
     // blocks access to AppLocker. If the sandbox does not allow access to the