diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 182db412..fb2f93bb 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -283,7 +283,7 @@ static inline uint32_t last_set(uint32_t i)
 
 	if (!i)
 		return 0;
-	asm volatile ("bsr %0, %1" : "=r"(ret) : "r"(i));
+	asm volatile ("bsr %1, %0" : "=r"(ret) : "r"(i) : "flags");
 
 	return ret;
 }