diff --git a/lib/metalkit/bios.c b/lib/metalkit/bios.c
index b736850..7d517c6 100644
--- a/lib/metalkit/bios.c
+++ b/lib/metalkit/bios.c
@@ -157,6 +157,14 @@ BIOSCallInternal(void)
    asm volatile("BIOSTrampolineVector: \n"
                 "int $0xFF");
 
+   /*
+    * Some BIOS routines will turn interrupts back on. If an interrupt
+    * occurs while we're partway through our 16-to-32 transition
+    * below, any interrupts will cause the ISR to fault, so we must
+    * make sure interrupts are still off.
+    */
+   asm volatile("cli");
+
    /*
     * Push Regs back onto the stack.
     */