diff --git a/sdk/xtdk/amd64/xtstruct.h b/sdk/xtdk/amd64/xtstruct.h
new file mode 100644
index 0000000..bb6087e
--- /dev/null
+++ b/sdk/xtdk/amd64/xtstruct.h
@@ -0,0 +1,15 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtdk/amd64/xtstruct.h
+ * DESCRIPTION:     XT structures forward references specific to AMD64 architecture
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#ifndef __XTDK_AMD64_XTSTRUCT_H
+#define __XTDK_AMD64_XTSTRUCT_H
+
+
+/* Architecture-related structures forward references */
+
+#endif /* __XTDK_AMD64_XTSTRUCT_H */
diff --git a/sdk/xtdk/i686/xtstruct.h b/sdk/xtdk/i686/xtstruct.h
new file mode 100644
index 0000000..0e6b775
--- /dev/null
+++ b/sdk/xtdk/i686/xtstruct.h
@@ -0,0 +1,15 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtdk/i686/xtstruct.h
+ * DESCRIPTION:     XT structures forward references specific to i686 architecture
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#ifndef __XTDK_I686_XTSTRUCT_H
+#define __XTDK_I686_XTSTRUCT_H
+
+
+/* Architecture-related structures forward references */
+
+#endif /* __XTDK_I686_XTSTRUCT_H */
diff --git a/sdk/xtdk/xtcommon.h b/sdk/xtdk/xtcommon.h
new file mode 100644
index 0000000..41d4b11
--- /dev/null
+++ b/sdk/xtdk/xtcommon.h
@@ -0,0 +1,37 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtdk/xtcommon.h
+ * DESCRIPTION:     Basic and common XT structures for kernel and user modes
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#ifndef __XTDK_XTCOMMON_H
+#define __XTDK_XTCOMMON_H
+
+#include "xttypes.h"
+#include "xtstruct.h"
+
+
+/* Double linked list structure definition */
+typedef struct _LIST_ENTRY
+{
+    PLIST_ENTRY Flink;
+    PLIST_ENTRY Blink;
+} LIST_ENTRY, *PLIST_ENTRY;
+
+/* 32-bit double linked list structure definition */
+typedef struct _LIST_ENTRY32
+{
+    ULONG Flink;
+    ULONG Blink;
+} LIST_ENTRY32, *PLIST_ENTRY32;
+
+/* 64-bit double linked list structure definition */
+typedef struct _LIST_ENTRY64
+{
+    ULONGLONG Flink;
+    ULONGLONG Blink;
+} LIST_ENTRY64, *PLIST_ENTRY64;
+
+#endif /* __XTDK_XTCOMMON_H */
diff --git a/sdk/xtdk/xtdefs.h b/sdk/xtdk/xtdefs.h
index c53b38d..b741c76 100644
--- a/sdk/xtdk/xtdefs.h
+++ b/sdk/xtdk/xtdefs.h
@@ -6,8 +6,8 @@
  * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
  */
 
-#ifndef __XTDK_XTBASE_H
-#define __XTDK_XTBASE_H
+#ifndef __XTDK_XTDEFS_H
+#define __XTDK_XTDEFS_H
 
 
 /* Routines and arguments modifiers */
@@ -82,4 +82,4 @@ typedef __builtin_va_list VA_LIST;
 #define UlongToHandle(Var)                     ((HANDLE)(ULONG_PTR)Var)
 #define UlongToPtr(Var)                        ((PVOID)(ULONG_PTR)Var)
 
-#endif /* __XTDK_XTBASE_H */
+#endif /* __XTDK_XTDEFS_H */
diff --git a/sdk/xtdk/xtkmapi.h b/sdk/xtdk/xtkmapi.h
index 43b5cde..e4a14d5 100644
--- a/sdk/xtdk/xtkmapi.h
+++ b/sdk/xtdk/xtkmapi.h
@@ -11,3 +11,12 @@
 #include "xttypes.h"
 #include "xtdefs.h"
 #include "xtstatus.h"
+
+/* XT forward references */
+#include "xtstruct.h"
+
+/* Architecture-specific XT forward references */
+#include ARCH_HEADER(xtstruct.h)
+
+/* Architecture-independent XT API */
+#include "xtcommon.h"
diff --git a/sdk/xtdk/xtstruct.h b/sdk/xtdk/xtstruct.h
new file mode 100644
index 0000000..c3da205
--- /dev/null
+++ b/sdk/xtdk/xtstruct.h
@@ -0,0 +1,18 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            sdk/xtdk/xtstruct.h
+ * DESCRIPTION:     XT structures forward references
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#ifndef __XTDK_XTSTRUCT_H
+#define __XTDK_XTSTRUCT_H
+
+
+/* Structures forward references */
+typedef struct _LIST_ENTRY LIST_ENTRY, *PLIST_ENTRY;
+typedef struct _LIST_ENTRY32 LIST_ENTRY32, *PLIST_ENTRY32;
+typedef struct _LIST_ENTRY64 LIST_ENTRY64, *PLIST_ENTRY64;
+
+#endif /* __XTDK_XTSTRUCT_H */