diff --git a/sys/boot/i386/pxeldr/pxeldr.S b/sys/boot/i386/pxeldr/pxeldr.S
index 65bc160..121984c 100644
--- a/sys/boot/i386/pxeldr/pxeldr.S
+++ b/sys/boot/i386/pxeldr/pxeldr.S
@@ -240,7 +240,10 @@ seta20.1:	inc %cx				# Increment, overflow?
 		jnz seta20.1			# Yes
 		movb $0xd1,%al			# Command: Write
 		outb %al,$0x64			#  output port
-seta20.2:	inb $0x64,%al			# Get status
+		xor %cx,%cx			# Clear
+seta20.2:	inc %cx				# Increment, overflow?
+		jz seta20.3			# Yes
+		inb $0x64,%al			# Get status
 		testb $0x2,%al			# Busy?
 		jnz seta20.2			# Yes
 		movb $0xdf,%al			# Enable