#define isBLANK_LC_utf8(c) isBLANK(c) /* could be wrong */
#ifdef EBCDIC
-# define toCTRL(c) Perl_ebcdic_control(c)
+# ifdef PERL_IMPLICIT_CONTEXT
+# define toCTRL(c) Perl_ebcdic_control(aTHX_ c)
+# else
+# define toCTRL Perl_ebcdic_control
+# endif
#else
/* This conversion works both ways, strangely enough. */
# define toCTRL(c) (toUPPER(c) ^ 64)