diff --git a/inc/efiapi.h b/inc/efiapi.h
index 1f2f479..778d513 100644
--- a/inc/efiapi.h
+++ b/inc/efiapi.h
@@ -24,8 +24,10 @@ Revision History
 // EFI Specification Revision
 //
 
+#define EFI_SPECIFICATION_REVISION_MAJORMINOR(major, minor) ((major<<16) | (minor))
 #define EFI_SPECIFICATION_MAJOR_REVISION 1
 #define EFI_SPECIFICATION_MINOR_REVISION 02
+#define EFI_SPECIFICATION_VERSION EFI_SPECIFICATION_REVISION_MAJORMINOR(EFI_SPECIFICATION_MAJOR_REVISION, EFI_SPECIFICATION_MINOR_REVISION)
 
 //
 // Declare forward referenced data structures
@@ -771,10 +773,22 @@ typedef struct _EFI_TABLE_HEADER {
 // EFI Runtime Serivces Table
 //
 
-#define EFI_RUNTIME_SERVICES_SIGNATURE  0x56524553544e5552
-#define EFI_1_10_RUNTIME_SERVICES_REVISION ((1<<16) | (10))
-#define EFI_2_00_RUNTIME_SERVICES_REVISION ((2<<16) | (0))
-#define EFI_RUNTIME_SERVICES_REVISION   (EFI_SPECIFICATION_MAJOR_REVISION<<16) | (EFI_SPECIFICATION_MINOR_REVISION)
+#define EFI_RUNTIME_SERVICES_SIGNATURE      0x56524553544e5552
+#define EFI_1_02_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 02)
+#define EFI_1_10_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 10)
+#define EFI_2_00_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 00)
+#define EFI_2_10_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 10)
+#define EFI_2_20_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 20)
+#define EFI_2_30_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 30)
+#define EFI_2_31_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 31)
+#define EFI_2_40_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 40)
+#define EFI_2_50_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 50)
+#define EFI_2_60_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 60)
+#define EFI_2_70_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 70)
+#define EFI_2_80_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 80)
+#define EFI_2_90_RUNTIME_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 90)
+#define EFI_2_100_RUNTIME_SERVICES_REVISION EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 100)
+#define EFI_RUNTIME_SERVICES_REVISION       EFI_SPECIFICATION_VERSION
 
 typedef struct  {
     EFI_TABLE_HEADER                Hdr;
@@ -820,10 +834,22 @@ typedef struct  {
 // EFI Boot Services Table
 //
 
-#define EFI_BOOT_SERVICES_SIGNATURE     0x56524553544f4f42
-#define EFI_1_10_BOOT_SERVICES_REVISION ((1<<16) | (10))
-#define EFI_2_00_BOOT_SERVICES_REVISION ((2<<16) | (0))
-#define EFI_BOOT_SERVICES_REVISION      (EFI_SPECIFICATION_MAJOR_REVISION<<16) | (EFI_SPECIFICATION_MINOR_REVISION)
+#define EFI_BOOT_SERVICES_SIGNATURE      0x56524553544f4f42
+#define EFI_1_02_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 02)
+#define EFI_1_10_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 10)
+#define EFI_2_00_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 00)
+#define EFI_2_10_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 10)
+#define EFI_2_20_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 20)
+#define EFI_2_30_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 30)
+#define EFI_2_31_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 31)
+#define EFI_2_40_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 40)
+#define EFI_2_50_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 50)
+#define EFI_2_60_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 60)
+#define EFI_2_70_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 70)
+#define EFI_2_80_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 80)
+#define EFI_2_90_BOOT_SERVICES_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 90)
+#define EFI_2_100_BOOT_SERVICES_REVISION EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 100)
+#define EFI_BOOT_SERVICES_REVISION       EFI_SPECIFICATION_VERSION
 
 typedef struct _EFI_BOOT_SERVICES {
 
@@ -965,10 +991,21 @@ typedef struct _EFI_CONFIGURATION_TABLE {
 
 
 #define EFI_SYSTEM_TABLE_SIGNATURE      0x5453595320494249
-#define EFI_1_02_SYSTEM_TABLE_REVISION ((1<<16) | (02))
-#define EFI_1_10_SYSTEM_TABLE_REVISION ((1<<16) | (10))
-#define EFI_2_00_SYSTEM_TABLE_REVISION ((2<<16) | (0))
-#define EFI_SYSTEM_TABLE_REVISION      (EFI_SPECIFICATION_MAJOR_REVISION<<16) | (EFI_SPECIFICATION_MINOR_REVISION)
+#define EFI_1_02_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 02)
+#define EFI_1_10_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(1, 10)
+#define EFI_2_00_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 00)
+#define EFI_2_10_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 10)
+#define EFI_2_20_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 20)
+#define EFI_2_30_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 30)
+#define EFI_2_31_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 31)
+#define EFI_2_40_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 40)
+#define EFI_2_50_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 50)
+#define EFI_2_60_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 60)
+#define EFI_2_70_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 70)
+#define EFI_2_80_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 80)
+#define EFI_2_90_SYSTEM_TABLE_REVISION  EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 90)
+#define EFI_2_100_SYSTEM_TABLE_REVISION EFI_SPECIFICATION_REVISION_MAJORMINOR(2, 100)
+#define EFI_SYSTEM_TABLE_REVISION       EFI_SPECIFICATION_VERSION
 
 typedef struct _EFI_SYSTEM_TABLE {
     EFI_TABLE_HEADER                Hdr;