diff --git a/perl.h b/perl.h
index 29d12696b50d..1b14e9c49a62 100644
--- a/perl.h
+++ b/perl.h
@@ -6411,7 +6411,15 @@ argument list, like this:
 
 On threaded perls not operating with thread-safe functionality, this macro uses
 a mutex to force a critical section.  Therefore the matching RESTORE should be
-close by, and guaranteed to be called.
+close by, and guaranteed to be called; see L</WITH_LC_NUMERIC_SET_TO_NEEDED>
+for a more contained way to ensure that.
+
+=for apidoc Am|void|STORE_LC_NUMERIC_SET_TO_NEEDED_IN|bool in_lc_numeric
+
+Same as L</STORE_LC_NUMERIC_SET_TO_NEEDED_IN> with in_lc_numeric provided
+as the precalculated value of C<IN_LC(LC_NUMERIC)>. It is the caller's
+responsibility to ensure that the status of C<PL_compiling> and C<PL_hints>
+cannot have changed since the precalculation.
 
 =for apidoc Am|void|RESTORE_LC_NUMERIC
 
@@ -6455,6 +6463,13 @@ is equivalent to:
 #endif
   }
 
+=for apidoc Am|void|WITH_LC_NUMERIC_SET_TO_NEEDED_IN|bool in_lc_numeric
+
+Same as L</WITH_LC_NUMERIC_SET_TO_NEEDED> with in_lc_numeric provided
+as the precalculated value of C<IN_LC(LC_NUMERIC)>. It is the caller's
+responsibility to ensure that the status of C<PL_compiling> and C<PL_hints>
+cannot have changed since the precalculation.
+
 =cut
 
 */
@@ -6482,12 +6497,13 @@ is equivalent to:
 #  define DECLARATION_FOR_LC_NUMERIC_MANIPULATION                           \
     void (*_restore_LC_NUMERIC_function)(pTHX) = NULL
 
-#  define STORE_LC_NUMERIC_SET_TO_NEEDED()                                  \
+#  define STORE_LC_NUMERIC_SET_TO_NEEDED_IN(in)                             \
         STMT_START {                                                        \
+            bool _in_lc_numeric = (in);                                     \
             LC_NUMERIC_LOCK(                                                \
-                    (   (  IN_LC(LC_NUMERIC) && _NOT_IN_NUMERIC_UNDERLYING) \
-                     || (! IN_LC(LC_NUMERIC) && _NOT_IN_NUMERIC_STANDARD)));\
-            if (IN_LC(LC_NUMERIC)) {                                        \
+                    (   (  _in_lc_numeric && _NOT_IN_NUMERIC_UNDERLYING)    \
+                     || (! _in_lc_numeric && _NOT_IN_NUMERIC_STANDARD)));   \
+            if (_in_lc_numeric) {                                           \
                 if (_NOT_IN_NUMERIC_UNDERLYING) {                           \
                     Perl_set_numeric_underlying(aTHX);                      \
                     _restore_LC_NUMERIC_function                            \
@@ -6503,6 +6519,9 @@ is equivalent to:
             }                                                               \
         } STMT_END
 
+#  define STORE_LC_NUMERIC_SET_TO_NEEDED() \
+        STORE_LC_NUMERIC_SET_TO_NEEDED_IN(IN_LC(LC_NUMERIC))
+
 #  define RESTORE_LC_NUMERIC()                                              \
         STMT_START {                                                        \
             if (_restore_LC_NUMERIC_function) {                             \
@@ -6577,14 +6596,17 @@ is equivalent to:
             __FILE__, __LINE__, PL_numeric_standard));                      \
         } STMT_END
 
-#  define WITH_LC_NUMERIC_SET_TO_NEEDED(block)                              \
+#  define WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric, block)            \
         STMT_START {                                                        \
             DECLARATION_FOR_LC_NUMERIC_MANIPULATION;                        \
-            STORE_LC_NUMERIC_SET_TO_NEEDED();                               \
+            STORE_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric);               \
             block;                                                          \
             RESTORE_LC_NUMERIC();                                           \
         } STMT_END;
 
+#  define WITH_LC_NUMERIC_SET_TO_NEEDED(block) \
+        WITH_LC_NUMERIC_SET_TO_NEEDED_IN(IN_LC(LC_NUMERIC), block)
+
 #else /* !USE_LOCALE_NUMERIC */
 
 #  define SET_NUMERIC_STANDARD()
@@ -6593,10 +6615,13 @@ is equivalent to:
 #  define DECLARATION_FOR_LC_NUMERIC_MANIPULATION
 #  define STORE_LC_NUMERIC_SET_STANDARD()
 #  define STORE_LC_NUMERIC_FORCE_TO_UNDERLYING()
+#  define STORE_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric)
 #  define STORE_LC_NUMERIC_SET_TO_NEEDED()
 #  define RESTORE_LC_NUMERIC()
 #  define LOCK_LC_NUMERIC_STANDARD()
 #  define UNLOCK_LC_NUMERIC_STANDARD()
+#  define WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric, block) \
+    STMT_START { block; } STMT_END
 #  define WITH_LC_NUMERIC_SET_TO_NEEDED(block) \
     STMT_START { block; } STMT_END
 
diff --git a/sv.c b/sv.c
index ef2c71126c9e..df0b601650ca 100644
--- a/sv.c
+++ b/sv.c
@@ -11784,7 +11784,7 @@ S_format_hexfp(pTHX_ char * const buf, const STRLEN bufsize, const char c,
 #else
         if (in_lc_numeric) {
             STRLEN n;
-            WITH_LC_NUMERIC_SET_TO_NEEDED({
+            WITH_LC_NUMERIC_SET_TO_NEEDED_IN(TRUE, {
                 const char* r = SvPV(PL_numeric_radix_sv, n);
                 Copy(r, p, n, char);
             });
@@ -12978,7 +12978,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
             }
 
             if (in_lc_numeric) {
-                WITH_LC_NUMERIC_SET_TO_NEEDED({
+                WITH_LC_NUMERIC_SET_TO_NEEDED_IN(TRUE, {
                     /* this can't wrap unless PL_numeric_radix_sv is a string
                      * consuming virtually all the 32-bit or 64-bit address
                      * space
@@ -13071,7 +13071,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                 && !fill
                 && intsize != 'q'
             ) {
-                WITH_LC_NUMERIC_SET_TO_NEEDED(
+                WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric,
                     SNPRINTF_G(fv, ebuf, sizeof(ebuf), precis)
                 );
                 elen = strlen(ebuf);
@@ -13174,7 +13174,7 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                     const char* qfmt = quadmath_format_single(ptr);
                     if (!qfmt)
                         Perl_croak_nocontext("panic: quadmath invalid format \"%s\"", ptr);
-                    WITH_LC_NUMERIC_SET_TO_NEEDED(
+                    WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric,
                         elen = quadmath_snprintf(PL_efloatbuf, PL_efloatsize,
                                                  qfmt, nv);
                     );
@@ -13187,13 +13187,13 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                         Safefree(qfmt);
                 }
 #elif defined(HAS_LONG_DOUBLE)
-                WITH_LC_NUMERIC_SET_TO_NEEDED(
+                WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric,
                     elen = ((intsize == 'q')
                             ? my_snprintf(PL_efloatbuf, PL_efloatsize, ptr, fv)
                             : my_snprintf(PL_efloatbuf, PL_efloatsize, ptr, (double)fv))
                 );
 #else
-                WITH_LC_NUMERIC_SET_TO_NEEDED(
+                WITH_LC_NUMERIC_SET_TO_NEEDED_IN(in_lc_numeric,
                     elen = my_snprintf(PL_efloatbuf, PL_efloatsize, ptr, fv)
                 );
 #endif