diff --git a/src/Makefile b/src/Makefile
index a2279a94..151026d8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -297,6 +297,9 @@ else
 	M5=-mpentium
 	M4=-m486
 endif
+else
+	M5=-march=nocona
+	M4=-mnocona
 endif
 
 ifndef NOASM