diff --git a/ext/f2c_libs/arith.h b/ext/f2c_libs/arith.h
index 9841db38a..9746f9c1c 100644
--- a/ext/f2c_libs/arith.h
+++ b/ext/f2c_libs/arith.h
@@ -1,3 +1,3 @@
-#define IEEE_8087
-#define Arith_Kind_ASL 1
-#define NANCHECK
+#define IEEE_8087
+#define Arith_Kind_ASL 1
+#define Double_Align