diff --git a/sdk/xtdk/amd64/artypes.h b/sdk/xtdk/amd64/artypes.h
index e2ad86bc..d788e3f1 100644
--- a/sdk/xtdk/amd64/artypes.h
+++ b/sdk/xtdk/amd64/artypes.h
@@ -39,6 +39,7 @@
 #define CR4_PCE                                         0x00000100
 #define CR4_FXSR                                        0x00000200
 #define CR4_XMMEXCPT                                    0x00000400
+#define CR4_LA57                                        0x00001000
 #define CR4_RESERVED1                                   0x00001800
 #define CR4_VMXE                                        0x00002000
 #define CR4_SMXE                                        0x00004000
diff --git a/sdk/xtdk/i686/artypes.h b/sdk/xtdk/i686/artypes.h
index 5dab6e1d..4059286a 100644
--- a/sdk/xtdk/i686/artypes.h
+++ b/sdk/xtdk/i686/artypes.h
@@ -39,6 +39,7 @@
 #define CR4_PCE                                         0x00000100
 #define CR4_FXSR                                        0x00000200
 #define CR4_XMMEXCPT                                    0x00000400
+#define CR4_LA57                                        0x00001000
 #define CR4_RESERVED1                                   0x00001800
 #define CR4_VMXE                                        0x00002000
 #define CR4_SMXE                                        0x00004000