_COMPLEX_DEFINED should be defined for MSVC, otherwise complex is redefined inconsistently in . Mail from Akira, 31 Mar 2012 21:36:26. diff -ur pmx-2.6.18.orig/libf2c/f2c.h pmx-2.6.18/libf2c/f2c.h --- pmx-2.6.18.orig/libf2c/f2c.h 2012-04-09 18:24:12.000000000 +0200 +++ pmx-2.6.18/libf2c/f2c.h 2012-05-19 18:49:12.286432193 +0200 @@ -13,6 +13,9 @@ typedef short int shortint; typedef float real; typedef double doublereal; +#ifdef WIN32 +#define _COMPLEX_DEFINED 1 +#endif typedef struct { real r, i; } complex; typedef struct { doublereal r, i; } doublecomplex; typedef long int logical;