diff --git a/demos/Win32-MSVS/chcore.c b/demos/Win32-MSVS/chcore.c
index 99876b8d6..facdea31c 100644
--- a/demos/Win32-MSVS/chcore.c
+++ b/demos/Win32-MSVS/chcore.c
@@ -84,7 +84,7 @@ __declspec(naked) void __fastcall chSysHalt(void) {
   exit(2);
 }
 
-__declspec(naked) void __fastcall chSysSwitchI(Context *oldp, Context *newp) {
+__declspec(naked) void __fastcall chSysSwitchI(Thread *otp, Thread *ntp) {
 
   __asm {
     // Switch out code
@@ -92,9 +92,9 @@ __declspec(naked) void __fastcall chSysSwitchI(Context *oldp, Context *newp) {
     push    esi
     push    edi
     push    ebx
-    mov     dword ptr [ecx],esp
+    mov     dword ptr 16[ecx],esp
     // Switch in code
-    mov     esp,[edx]
+    mov     esp,16[edx]
     pop     ebx
     pop     edi
     pop     esi
diff --git a/demos/Win32-MSVS/chcore.h b/demos/Win32-MSVS/chcore.h
index b9fbb0147..18e96dc13 100644
--- a/demos/Win32-MSVS/chcore.h
+++ b/demos/Win32-MSVS/chcore.h
@@ -76,7 +76,7 @@ typedef struct {
 t_msg _IdleThread(void *p);
 
 void __fastcall chSysHalt(void);
-void __fastcall chSysSwitchI(Context *oldp, Context *newp);
+void __fastcall chSysSwitchI(Thread *otp, Thread *ntp);
 void __fastcall threadexit(void);
 
 #endif /* _CHCORE_H_ */
diff --git a/demos/Win32-MinGW/chcore.h b/demos/Win32-MinGW/chcore.h
index 43265326b..6bb2664f5 100644
--- a/demos/Win32-MinGW/chcore.h
+++ b/demos/Win32-MinGW/chcore.h
@@ -76,7 +76,7 @@ typedef struct {
 t_msg _IdleThread(void *p);
 
 __attribute__((fastcall)) void chSysHalt(void);
-__attribute__((fastcall)) void chSysSwitchI(Context *oldp, Context *newp);
+__attribute__((fastcall)) void chSysSwitchI(Thread *otp, Thread *ntp);
 __attribute__((fastcall)) void threadstart(void);
 
 #endif /* _CHCORE_H_ */
diff --git a/demos/Win32-MinGW/chcore2.s b/demos/Win32-MinGW/chcore2.s
index c8260e3e6..9334fbfdc 100644
--- a/demos/Win32-MinGW/chcore2.s
+++ b/demos/Win32-MinGW/chcore2.s
@@ -27,9 +27,9 @@
         push    %esi
         push    %edi
         push    %ebx
-        movl    %esp,(%ecx)
+        movl    %esp,16(%ecx)
         # Switch in
-        movl    (%edx),%esp
+        movl    16(%edx),%esp
         pop     %ebx
         pop     %edi
         pop     %esi