diff --git a/embed.fnc b/embed.fnc
index 8e32ba20ce..23614d1275 100644
--- a/embed.fnc
+++ b/embed.fnc
@@ -5366,18 +5366,18 @@ Ep	|SSize_t|study_chunk	|NN RExC_state_t *pRExC_state		\
 				|U32 depth				\
 				|bool was_mutate_ok
 # if defined(PERL_IN_REGCOMP_TRIE_C) && defined(DEBUGGING)
-ES	|void	|dump_trie	|NN const struct _reg_trie_data *trie	\
+ES	|void	|dump_trie	|NN const struct reg_trie_data_ *trie	\
 				|NULLOK HV *widecharmap 		\
 				|NN AV *revcharmap			\
 				|U32 depth
 ES	|void	|dump_trie_interim_list 				\
-				|NN const struct _reg_trie_data *trie	\
+				|NN const struct reg_trie_data_ *trie	\
 				|NULLOK HV *widecharmap 		\
 				|NN AV *revcharmap			\
 				|U32 next_alloc 			\
 				|U32 depth
 ES	|void	|dump_trie_interim_table				\
-				|NN const struct _reg_trie_data *trie	\
+				|NN const struct reg_trie_data_ *trie	\
 				|NULLOK HV *widecharmap 		\
 				|NN AV *revcharmap			\
 				|U32 next_alloc 			\
diff --git a/perl.h b/perl.h
index ee92716971..4e85a5a720 100644
--- a/perl.h
+++ b/perl.h
@@ -4574,7 +4574,7 @@ typedef struct regnode_charclass_posixl regnode_charclass_posixl;
 
 typedef struct regnode_ssc regnode_ssc;
 typedef struct RExC_state_t RExC_state_t;
-struct _reg_trie_data;
+struct reg_trie_data_;
 typedef struct scan_data_t scan_data_t;
 
 #endif
diff --git a/proto.h b/proto.h
index 64d50774ad..8dee442e08 100644
--- a/proto.h
+++ b/proto.h
@@ -8322,11 +8322,11 @@ Perl_study_chunk(pTHX_ RExC_state_t *pRExC_state, regnode **scanp, SSize_t *minl
         __attribute__visibility__("hidden");
 #   if defined(PERL_IN_REGCOMP_TRIE_C) && defined(DEBUGGING)
 STATIC void
-S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap, AV *revcharmap, U32 depth);
+S_dump_trie(pTHX_ const struct reg_trie_data_ *trie, HV *widecharmap, AV *revcharmap, U32 depth);
 STATIC void
-S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap, AV *revcharmap, U32 next_alloc, U32 depth);
+S_dump_trie_interim_list(pTHX_ const struct reg_trie_data_ *trie, HV *widecharmap, AV *revcharmap, U32 next_alloc, U32 depth);
 STATIC void
-S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap, AV *revcharmap, U32 next_alloc, U32 depth);
+S_dump_trie_interim_table(pTHX_ const struct reg_trie_data_ *trie, HV *widecharmap, AV *revcharmap, U32 next_alloc, U32 depth);
 #   endif
 # endif /* defined(PERL_CORE) || defined(PERL_EXT) */
 # if defined(PERL_IN_REGCOMP_TRIE_C) && defined(DEBUGGING)
diff --git a/regcomp.h b/regcomp.h
index 72c81d36f8..4f1600e94a 100644
--- a/regcomp.h
+++ b/regcomp.h
@@ -1233,7 +1233,7 @@ typedef struct reg_trie_trans_    reg_trie_trans;
    should be dealt with in pregfree.
    refcount is first in both this and _reg_ac_data to allow a space
    optimisation in Perl_regdupe.  */
-struct _reg_trie_data {
+struct reg_trie_data_ {
     U32             refcount;        /* number of times this trie is referenced */
     U32             lasttrans;       /* last valid transition element */
     U16             *charmap;        /* byte to charid lookup array */
@@ -1274,9 +1274,9 @@ struct _reg_trie_data {
 
 #define TRIE_WORDS_OFFSET 2
 
-typedef struct _reg_trie_data reg_trie_data;
+typedef struct reg_trie_data_ reg_trie_data;
 
-/* refcount is first in both this and _reg_trie_data to allow a space
+/* refcount is first in both this and reg_trie_data_ to allow a space
    optimisation in Perl_regdupe.  */
 struct _reg_ac_data {
     U32              refcount;
diff --git a/regcomp_trie.c b/regcomp_trie.c
index 7cd55023e7..f3863bcb83 100644
--- a/regcomp_trie.c
+++ b/regcomp_trie.c
@@ -48,7 +48,7 @@
 */
 
 STATIC void
-S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
+S_dump_trie(pTHX_ const struct reg_trie_data_ *trie, HV *widecharmap,
             AV *revcharmap, U32 depth)
 {
     U32 state;
@@ -142,7 +142,7 @@ S_dump_trie(pTHX_ const struct _reg_trie_data *trie, HV *widecharmap,
   Used for debugging make_trie().
 */
 STATIC void
-S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie,
+S_dump_trie_interim_list(pTHX_ const struct reg_trie_data_ *trie,
                          HV *widecharmap, AV *revcharmap, U32 next_alloc,
                          U32 depth)
 {
@@ -202,7 +202,7 @@ S_dump_trie_interim_list(pTHX_ const struct _reg_trie_data *trie,
   Used for debugging make_trie().
 */
 STATIC void
-S_dump_trie_interim_table(pTHX_ const struct _reg_trie_data *trie,
+S_dump_trie_interim_table(pTHX_ const struct reg_trie_data_ *trie,
                           HV *widecharmap, AV *revcharmap, U32 next_alloc,
                           U32 depth)
 {