diff --git a/perl.h b/perl.h
index b7df2caac6b6..adbb0185238e 100644
--- a/perl.h
+++ b/perl.h
@@ -7545,7 +7545,7 @@ the plain locale pragma without a parameter (S<C<use locale>>) is in effect.
       * and will do so if enabled.  The first takes a single code point
       * argument; the 2nd, is a pointer to the first byte of the UTF-8 encoded
       * string, and an end position which it won't try to read past */
-#    define _CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG(cp)                        \
+#    define CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG_(cp)                        \
         STMT_START {                                                        \
             if (! IN_UTF8_CTYPE_LOCALE && ckWARN(WARN_LOCALE)) {            \
                 Perl_warner(aTHX_ packWARN(WARN_LOCALE),                    \
@@ -7554,7 +7554,7 @@ the plain locale pragma without a parameter (S<C<use locale>>) is in effect.
             }                                                               \
         }  STMT_END
 
-#    define _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(s, send)                 \
+#    define CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(s, send)                 \
         STMT_START { /* Check if to warn before doing the conversion work */\
             if (! IN_UTF8_CTYPE_LOCALE && ckWARN(WARN_LOCALE)) {            \
                 UV cp;                                                      \
@@ -7581,8 +7581,8 @@ the plain locale pragma without a parameter (S<C<use locale>>) is in effect.
 #  define IN_LC_RUNTIME(category)          0
 #  define IN_LC(category)                  0
 #  define CHECK_AND_WARN_PROBLEMATIC_LOCALE_
-#  define _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(s, send)
-#  define _CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG(c)
+#  define CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(s, send)
+#  define CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG_(c)
 #endif
 
 #define locale_panic_via_(m, f, l)  Perl_locale_panic((m), __LINE__, f, l)
diff --git a/regexec.c b/regexec.c
index 364713893d2b..1d683338e96e 100644
--- a/regexec.c
+++ b/regexec.c
@@ -607,7 +607,7 @@ S_isFOO_utf8_lc(pTHX_ const U8 classnum, const U8* character, const U8* e)
                         EIGHT_BIT_UTF8_TO_NATIVE(*character, *(character + 1)));
     }
 
-    _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(character, e);
+    CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(character, e);
 
     switch ((char_class_number_) classnum) {
         case CC_ENUM_SPACE_:     return is_XPERLSPACE_high(character);
@@ -1807,7 +1807,7 @@ STMT_START {
     case trie_flu8:                                                                 \
         CHECK_AND_WARN_PROBLEMATIC_LOCALE_;                                         \
         if (UTF8_IS_ABOVE_LATIN1(*uc)) {                                            \
-            _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc_end);                     \
+            CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(uc, uc_end);                     \
         }                                                                           \
         goto do_trie_utf8_fold;                                                     \
     case trie_utf8_exactfa_fold:                                                    \
@@ -1853,7 +1853,7 @@ STMT_START {
     case trie_utf8l:                                                                \
         CHECK_AND_WARN_PROBLEMATIC_LOCALE_;                                         \
         if (utf8_target && UTF8_IS_ABOVE_LATIN1(*uc)) {                             \
-            _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(uc, uc_end);                     \
+            CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(uc, uc_end);                     \
         }                                                                           \
         /* FALLTHROUGH */                                                           \
     case trie_utf8:                                                                 \
@@ -6730,7 +6730,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
                         /* We only output for EXACTL, as we let the folder
                          * output this message for EXACTFLU8 to avoid
                          * duplication */
-                        _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(locinput,
+                        CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(locinput,
                                                                reginfo->strend);
                     }
                 }
@@ -7054,7 +7054,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
              * just to check for this warning is worth it.  So this just checks
              * the first character */
             if (utf8_target && UTF8_IS_ABOVE_LATIN1(*locinput)) {
-                _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(locinput, reginfo->strend);
+                CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(locinput, reginfo->strend);
             }
             goto do_exact;
         case EXACT_REQ8:
@@ -7740,7 +7740,7 @@ S_regmatch(pTHX_ regmatch_info *reginfo, char *startpos, regnode *prog)
 
             if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(locinput, reginfo->strend)) {
                 /* An above Latin-1 code point, or malformed */
-                _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(locinput,
+                CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(locinput,
                                                        reginfo->strend);
                 goto utf8_posix_above_latin1;
             }
@@ -10305,7 +10305,7 @@ S_regrepeat(pTHX_ regexp *prog, char **startposp, const regnode *p,
 
       case EXACTL_t8:
         if (UTF8_IS_ABOVE_LATIN1(*scan)) {
-            _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(scan, loceol);
+            CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(scan, loceol);
         }
         /* FALLTHROUGH */
 
@@ -10926,7 +10926,7 @@ S_reginclass(pTHX_ regexp * const prog, const regnode * const n, const U8* const
             &&  (OP(n) == ANYOFL || OP(n) == ANYOFPOSIXL)
             && ! (flags & ANYOFL_UTF8_LOCALE_REQD))
         {
-            _CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG(c);
+            CHECK_AND_OUTPUT_WIDE_LOCALE_CP_MSG_(c);
         }
     }
 
diff --git a/utf8.c b/utf8.c
index bfab721cb55b..f3d7eebcb04d 100644
--- a/utf8.c
+++ b/utf8.c
@@ -4152,7 +4152,7 @@ S_check_locale_boundary_crossing(pTHX_ const U8* const p, const UV result,
         }
 
         /* Here, no characters crossed, result is ok as-is, but we warn. */
-        _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(p, p + UTF8SKIP(p));
+        CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG_(p, p + UTF8SKIP(p));
         return result;
     }