diff --git a/perl.h b/perl.h
index 0dbfd7cc40c5..7e9ee21e4faa 100644
--- a/perl.h
+++ b/perl.h
@@ -7098,14 +7098,16 @@ cannot have changed since the precalculation.
             LC_NUMERIC_UNLOCK;                                              \
         } STMT_END
 
-/* The next two macros set unconditionally.  These should be rarely used, and
- * only after being sure that this is what is needed */
+/* The next two macros should be rarely used, and only after being sure that
+ * this is what is needed */
 #  define SET_NUMERIC_STANDARD()                                            \
 	STMT_START {                                                        \
             DEBUG_Lv(PerlIO_printf(Perl_debug_log,                          \
                                "%s: %d: lc_numeric standard=%d\n",          \
                                 __FILE__, __LINE__, PL_numeric_standard));  \
-            Perl_set_numeric_standard(aTHX);                                \
+            if (NOT_IN_NUMERIC_STANDARD_) {                                 \
+                Perl_set_numeric_standard(aTHX);                            \
+            }                                                               \
             DEBUG_Lv(PerlIO_printf(Perl_debug_log,                          \
                                  "%s: %d: lc_numeric standard=%d\n",        \
                                  __FILE__, __LINE__, PL_numeric_standard)); \