diff --git a/xtoskrnl/ar/amd64/procsup.c b/xtoskrnl/ar/amd64/procsup.c
index 1ec760c..d3bf347 100644
--- a/xtoskrnl/ar/amd64/procsup.c
+++ b/xtoskrnl/ar/amd64/procsup.c
@@ -197,9 +197,8 @@ ArpInitializeTss(IN PKPROCESSOR_BLOCK ProcessorBlock)
     /* Setup I/O map and stacks for ring0 & traps */
     ProcessorBlock->TssBase->IoMapBase = sizeof(KTSS);
     ProcessorBlock->TssBase->Rsp0 = KeInitializationBlock->KernelBootStack;
-    ProcessorBlock->TssBase->Ist[1] = KeInitializationBlock->KernelFaultStack;
-    ProcessorBlock->TssBase->Ist[2] = KeInitializationBlock->KernelFaultStack;
-    ProcessorBlock->TssBase->Ist[3] = KeInitializationBlock->KernelFaultStack;
+    ProcessorBlock->TssBase->Ist[KIDT_IST_PANIC] = KeInitializationBlock->KernelFaultStack;
+    ProcessorBlock->TssBase->Ist[KIDT_IST_MCA] = KeInitializationBlock->KernelFaultStack;
 }
 
 /**