diff --git a/sdk/xtdk/amd64/rtltypes.h b/sdk/xtdk/amd64/rtltypes.h
index fbba3e2..9ca5f2b 100644
--- a/sdk/xtdk/amd64/rtltypes.h
+++ b/sdk/xtdk/amd64/rtltypes.h
@@ -3,7 +3,7 @@
  * COPYRIGHT:       See COPYING.md in the top level directory
  * FILE:            sdk/xtdk/amd64/rtltypes.h
  * DESCRIPTION:     Runtime library structures definitions for AMD64 architecture
- * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
  */
 
 #ifndef __XTDK_AMD64_RTLTYPES_H
@@ -16,11 +16,41 @@
 /* C/C++ specific code */
 #ifndef __XTOS_ASSEMBLER__
 
-/* Header for a sequenced single linked list structure definition */
-typedef struct _SINGLE_LIST_HEADER
+/* Header for a sequenced single linked list union definition */
+typedef union _SINGLE_LIST_HEADER
 {
-    ULONGLONG Alignment;
-    ULONGLONG Region;
+    struct
+    {
+        ULONGLONG Alignment;
+        ULONGLONG Region;
+    };
+    struct
+    {
+        ULONGLONG Depth:16;
+        ULONGLONG Sequence:9;
+        ULONGLONG NextEntry:39;
+        ULONGLONG HeaderType:1;
+        ULONGLONG Init:1;
+        ULONGLONG Reserved:59;
+        ULONGLONG Region:3;
+    } Header8;
+    struct
+    {
+        ULONGLONG Depth:16;
+        ULONGLONG Sequence:48;
+        ULONGLONG HeaderType:1;
+        ULONGLONG Init:1;
+        ULONGLONG Reserved:2;
+        ULONGLONG NextEntry:60;
+    } Header16;
+    struct
+    {
+        ULONGLONG Depth:16;
+        ULONGLONG Sequence:48;
+        ULONGLONG HeaderType:1;
+        ULONGLONG Reserved:3;
+        ULONGLONG NextEntry:60;
+    } Header64;
 } SINGLE_LIST_HEADER, *PSINGLE_LIST_HEADER;
 
 #endif /* __XTOS_ASSEMBLER__ */
diff --git a/sdk/xtdk/amd64/xtstruct.h b/sdk/xtdk/amd64/xtstruct.h
index 105eeb9..a393a95 100644
--- a/sdk/xtdk/amd64/xtstruct.h
+++ b/sdk/xtdk/amd64/xtstruct.h
@@ -72,7 +72,6 @@ typedef struct _MMPTE_SOFTWARE MMPTE_SOFTWARE, *PMMPTE_SOFTWARE;
 typedef struct _MMPTE_SUBSECTION MMPTE_SUBSECTION, *PMMPTE_SUBSECTION;
 typedef struct _MMPTE_TRANSITION MMPTE_TRANSITION, *PMMPTE_TRANSITION;
 typedef struct _POOL_DESCRIPTOR POOL_DESCRIPTOR, *PPOOL_DESCRIPTOR;
-typedef struct _SINGLE_LIST_HEADER SINGLE_LIST_HEADER, *PSINGLE_LIST_HEADER;
 typedef struct _THREAD_ENVIRONMENT_BLOCK THREAD_ENVIRONMENT_BLOCK, *PTHREAD_ENVIRONMENT_BLOCK;
 typedef struct _TIMER_CAPABILITIES TIMER_CAPABILITIES, *PTIMER_CAPABILITIES;
 
@@ -91,6 +90,7 @@ typedef union _PIC_I8259_ICW1 PIC_I8259_ICW1, *PPIC_I8259_ICW1;
 typedef union _PIC_I8259_ICW2 PIC_I8259_ICW2, *PPIC_I8259_ICW2;
 typedef union _PIC_I8259_ICW3 PIC_I8259_ICW3, *PPIC_I8259_ICW3;
 typedef union _PIC_I8259_ICW4 PIC_I8259_ICW4, *PPIC_I8259_ICW4;
+typedef union _SINGLE_LIST_HEADER SINGLE_LIST_HEADER, *PSINGLE_LIST_HEADER;
 
 #endif /* __XTOS_ASSEMBLER__ */
 #endif /* __XTDK_AMD64_XTSTRUCT_H */
diff --git a/sdk/xtdk/i686/rtltypes.h b/sdk/xtdk/i686/rtltypes.h
index ed7a93a..a8407ed 100644
--- a/sdk/xtdk/i686/rtltypes.h
+++ b/sdk/xtdk/i686/rtltypes.h
@@ -3,7 +3,7 @@
  * COPYRIGHT:       See COPYING.md in the top level directory
  * FILE:            sdk/xtdk/amd64/rtltypes.h
  * DESCRIPTION:     Runtime library structures definitions for i686 architecture
- * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
  */
 
 #ifndef __XTDK_I686_RTLTYPES_H