diff --git a/bochs/cpu/cpuid.cc b/bochs/cpu/cpuid.cc
index 53fdba5e3..436b85f3f 100644
--- a/bochs/cpu/cpuid.cc
+++ b/bochs/cpu/cpuid.cc
@@ -373,6 +373,8 @@ void bx_cpuid_t::get_ext_cpuid_leaf_8(cpuid_function_t *leaf) const
   leaf->eax = phy_addr_width | (lin_addr_width << 8);
 
   // [0:0] CLZERO support
+  // [1:1] Instruction Retired Counter support (???)
+  // [2:2] Error Pointer Zero/Restore (???)
   leaf->ebx = 0;
   if (is_cpu_extension_supported(BX_ISA_CLZERO))
     leaf->ebx |= 0x1;