diff --git a/reactos/include/ddk/winddk.h b/reactos/include/ddk/winddk.h
index bbd1f835a50..650f9d93241 100644
--- a/reactos/include/ddk/winddk.h
+++ b/reactos/include/ddk/winddk.h
@@ -396,7 +396,15 @@ extern POBJECT_TYPE NTSYSAPI LpcPortObjectType;
 extern POBJECT_TYPE NTSYSAPI MmSectionObjectType;
 extern POBJECT_TYPE NTSYSAPI SeTokenObjectType;
 
-extern NTOSAPI CCHAR KeNumberProcessors;
+#if (NTDDI_VERSION >= NTDDI_LONGHORN)
+extern volatile CCHAR NTSYSAPI KeNumberProcessors;
+#else
+#if (NTDDI_VERSION >= NTDDI_WINXP)
+extern CCHAR NTSYSAPI KeNumberProcessors;
+#else
+extern PCCHAR KeNumberProcessors;
+#endif
+#endif
 
 #define PROCESSOR_FEATURE_MAX 64
 #define MAX_WOW64_SHARED_ENTRIES 16
@@ -10442,7 +10450,7 @@ DbgBreakPointWithStatus(
 ULONG
 __cdecl
 DbgPrint(
-  IN PCH  Format,
+  IN PCCH  Format,
   IN ...);
 
 ULONG
@@ -10450,7 +10458,7 @@ __cdecl
 DbgPrintEx(
   IN ULONG  ComponentId,
   IN ULONG  Level,
-  IN PCH  Format,
+  IN PCCH  Format,
   IN ...);
 
 NTOSAPI
diff --git a/reactos/include/psdk/ntdef.h b/reactos/include/psdk/ntdef.h
index 87ca61cedaf..c2dfa45e510 100644
--- a/reactos/include/psdk/ntdef.h
+++ b/reactos/include/psdk/ntdef.h
@@ -63,6 +63,7 @@ typedef CONST STRING* PCOEM_STRING;
 typedef STRING CANSI_STRING;
 typedef PSTRING PCANSI_STRING;
 typedef LARGE_INTEGER PHYSICAL_ADDRESS, *PPHYSICAL_ADDRESS;
+typedef CONST CHAR *LPCCH, *PCCH;
 typedef enum _SECTION_INHERIT {
   ViewShare = 1,
   ViewUnmap = 2
diff --git a/reactos/include/reactos/libs/pseh/framebased.h b/reactos/include/reactos/libs/pseh/framebased.h
index 9e6d4a0304e..a68469b400f 100644
--- a/reactos/include/reactos/libs/pseh/framebased.h
+++ b/reactos/include/reactos/libs/pseh/framebased.h
@@ -45,7 +45,7 @@
 # define _SEHSetJmp setjmp
 # define _SEHJmpBuf_t jmp_buf
 #endif
-unsigned long DbgPrint(char * Format,...);
+unsigned long DbgPrint(const char * Format,...);
 typedef struct __SEHFrame
 {
  _SEHPortableFrame_t SEH_Header;