/* compatibility stuff for other compilers goes here */
-#if !defined(PERL_OBJECT) && defined(PERL_MEMBER_PTR_SIZE)
+#if !defined(PERL_OBJECT) && defined(PERL_CAPI) && defined(PERL_MEMBER_PTR_SIZE)
# define STRUCT_MGVTBL_DEFINITION \
struct mgvtbl { \
union { \
U8 op_flags; \
U8 op_private;
-#endif /* !PERL_OBJECT && PERL_MEMBER_PTR_SIZE */
+#endif /* !PERL_OBJECT && PERL_CAPI && PERL_MEMBER_PTR_SIZE */
START_EXTERN_C