diff --git a/arch/x86/kernel/entry32.asm b/arch/x86/kernel/entry32.asm
index 7443ff7f..c5096863 100644
--- a/arch/x86/kernel/entry32.asm
+++ b/arch/x86/kernel/entry32.asm
@@ -799,8 +799,14 @@ common_switch:
     xor eax, eax
 %endif
     add eax, task_state_segments
-    ; set esp0 in TSS
-    mov [eax+4], esp
+ 
+    ; determine and set esp0 in TSS
+    mov ebx, esp
+    mov ecx, KERNEL_STACK_SIZE-1
+    not ecx
+    and ebx, ecx
+    add ebx, KERNEL_STACK_SIZE-16
+    mov [eax+4], ebx
 
     ; call cleanup code
     call finish_task_switch