diff --git a/lib/cerf.h b/lib/cerf.h
index 28576ab..c9bc6dd 100644
--- a/lib/cerf.h
+++ b/lib/cerf.h
@@ -55,25 +55,23 @@
      typedef double _Complex _cerf_cmplx;
 #  endif
 
-#  undef __BEGIN_DECLS
-#  undef __END_DECLS
 #  ifdef CERF_AS_CPP
 #    ifndef __cplusplus
        impossible_case
 #    endif
-#    define __BEGIN_DECLS
-#    define __END_DECLS
+#    define LIBCERF_BEGIN_DECLS
+#    define LIBCERF_END_DECLS
 #  else
 #    ifdef __cplusplus // this include file called from C++ while library is compiled as C
-#      define __BEGIN_DECLS extern "C" {
-#      define __END_DECLS }
+#      define LIBCERF_BEGIN_DECLS extern "C" {
+#      define LIBCERF_END_DECLS }
 #    else
-#      define __BEGIN_DECLS
-#      define __END_DECLS
+#      define LIBCERF_BEGIN_DECLS
+#      define LIBCERF_END_DECLS
 #    endif
 #  endif
 
-__BEGIN_DECLS
+LIBCERF_BEGIN_DECLS
 
 #if _WIN32
 #define EXPORT __declspec(dllexport)
@@ -111,5 +109,5 @@ EXPORT double voigt(double x, double sigma, double gamma);
 // compute the full width at half maximum of the Voigt function
 EXPORT double voigt_hwhm(double sigma, double gamma);
 
-__END_DECLS
+LIBCERF_END_DECLS
 #endif /* __CERF_H__ */