diff --git a/headers/private/system/arch/x86/arch_commpage_defs.h b/headers/private/system/arch/x86/arch_commpage_defs.h
index df013c510e..a61678dd03 100644
--- a/headers/private/system/arch/x86/arch_commpage_defs.h
+++ b/headers/private/system/arch/x86/arch_commpage_defs.h
@@ -11,6 +11,7 @@
 
 #define COMMPAGE_ENTRY_X86_SYSCALL	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 0)
 #define COMMPAGE_ENTRY_X86_MEMCPY	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 1)
+#define COMMPAGE_ENTRY_X86_MEMSET	(COMMPAGE_ENTRY_FIRST_ARCH_SPECIFIC + 2)
 
 #define ARCH_USER_COMMPAGE_ADDR (0xffff0000)