diff --git a/src/os_vms_conf.h b/src/os_vms_conf.h
index 71f1df2..d70ab61 100644
--- a/src/os_vms_conf.h
+++ b/src/os_vms_conf.h
@@ -114,6 +114,8 @@
 #define HAVE_PUTENV
 #define HAVE_SETENV
 #define HAVE_SETJMP_H
+#define HAVE_MATH_H
+#define HAVE_FLOAT_FUNCS
 
 #undef	HAVE_DIRENT_H
 #undef	HAVE_SYS_NDIR_H