diff --git a/prism/Makefile b/prism/Makefile
index 3d51b5a2..82c708a2 100644
--- a/prism/Makefile
+++ b/prism/Makefile
@@ -156,7 +156,7 @@ ifeq ($(OSTYPE),linux)
 		LDFLAGS = $(CUDD_XCFLAGS) $(OPTIMISE)
 		BINDISTSUFFIX = linux64
 	else
-		CUDD_XCFLAGS = -m32 -mtune=native -malign-double -DHAVE_IEEE_754 -DBSD $(DEBUG)
+		CUDD_XCFLAGS = -m32 -malign-double -DHAVE_IEEE_754 -DBSD $(DEBUG)
 		CFLAGS = $(CUDD_XCFLAGS) $(OPTIMISE)
 		CPPFLAGS = $(CUDD_XCFLAGS) $(OPTIMISE)
 		LDFLAGS = $(CUDD_XCFLAGS) $(OPTIMISE)