diff --git a/vpi_user.h b/vpi_user.h
index e0d25de96..154747f0f 100644
--- a/vpi_user.h
+++ b/vpi_user.h
@@ -362,7 +362,7 @@ typedef struct t_vpi_delay  {
 #   define vpiSysFuncReal  vpiRealFunc
 #   define vpiSysFuncTime  vpiTimeFunc
 #   define vpiSysFuncSized vpiSizedFunc
-#define vpiUserDefn       49
+#define vpiUserDefn       45
 #define vpiAutomatic      50
 #define vpiConstantSelect 53
 #define vpiSigned         65