diff --git a/boot.subx b/boot.subx
index 06a9a426..5b98a110 100644
--- a/boot.subx
+++ b/boot.subx
@@ -339,6 +339,7 @@ keyboard-interrupt-handler:
   # prologue
   fa/disable-interrupts
   60/push-all-registers
+  9c/push-flags
   # acknowledge interrupt
   b0/copy-to-al 0x20/imm8
   e6/write-al-into-port 0x20/imm8
@@ -450,6 +451,7 @@ $keyboard-interrupt-handler:select-map-done:
   }
 $keyboard-interrupt-handler:epilogue:
   # epilogue
+  9d/pop-flags
   61/pop-all-registers
   fb/enable-interrupts
   cf/return-from-interrupt