diff --git a/spinlock_x86.h b/spinlock_x86.h
index 0da99d8..b816269 100644
--- a/spinlock_x86.h
+++ b/spinlock_x86.h
@@ -29,10 +29,10 @@
         (
          "\n1:\t" \
          "cmpb $0,%1\n\t" \
-         "jne 1b\n\t" \
+         "ja 1b\n\t" \
          "xchgb %b0, %1\n\t" \
          "cmpb $0,%0\n" \
-         "jne 1b\n\t"
+         "ja 1b\n\t"
          :"=q"(oldval), "=m"(*lock)
          : "0"(1)
          : "memory");