diff --git a/bn_mp_set_double.c b/bn_mp_set_double.c
index 8a148e9..c78cb22 100644
--- a/bn_mp_set_double.c
+++ b/bn_mp_set_double.c
@@ -49,6 +49,7 @@ int mp_set_double(mp_int *a, double b)
    return MP_OKAY;
 }
 #else
+/* pragma message() not supported by several compilers (in mostly older but still used versions) */
 #  ifdef _MSC_VER
 #    pragma message("mp_set_double implementation is only available on platforms with IEEE754 floating point format")
 #  else