diff --git a/f2c.h b/f2c.h
index b94ee7c8..2390d41b 100644
--- a/f2c.h
+++ b/f2c.h
@@ -12,7 +12,9 @@ typedef unsigned long int uinteger;
 typedef char *address;
 typedef short int shortint;
 typedef float real;
-typedef double doublereal;
+/* avoid irritating warnings when math functions are used, M.Z.08.2001 */
+#define doublereal double
+/* typedef double doublereal; */
 typedef struct { real r, i; } complex;
 typedef struct { doublereal r, i; } doublecomplex;
 typedef long int logical;