diff --git a/locale.c b/locale.c
index b26322a6b2d2..57f6611b4c6b 100644
--- a/locale.c
+++ b/locale.c
@@ -43,6 +43,19 @@
  * this end, and is retained, #ifdef'd out.
  */
 
+/* If the environment says to, we can output debugging information during
+ * initialization.  This is done before option parsing, and before any thread
+ * creation, so can be a file-level static.  (Must come before #including
+ * perl.h) */
+#ifdef DEBUGGING
+static int debug_initialization = 0;
+#  define DEBUG_INITIALIZATION_set(v) (debug_initialization = v)
+#  define DEBUG_LOCALE_INITIALIZATION_  debug_initialization
+#else
+#  define debug_initialization 0
+#  define DEBUG_INITIALIZATION_set(v)
+#endif
+
 #include "EXTERN.h"
 #define PERL_IN_LOCALE_C
 #include "perl_langinfo.h"
@@ -57,17 +70,6 @@
 #  include <wctype.h>
 #endif
 
-/* If the environment says to, we can output debugging information during
- * initialization.  This is done before option parsing, and before any thread
- * creation, so can be a file-level static */
-#if ! defined(DEBUGGING)
-#  define debug_initialization 0
-#  define DEBUG_INITIALIZATION_set(v)
-#else
-static bool debug_initialization = FALSE;
-#  define DEBUG_INITIALIZATION_set(v) (debug_initialization = v)
-#endif
-
 
 /* Returns the Unix errno portion; ignoring any others.  This is a macro here
  * instead of putting it into perl.h, because unclear to khw what should be
diff --git a/perl.h b/perl.h
index 17a21a1c420f..a16be2095193 100644
--- a/perl.h
+++ b/perl.h
@@ -4417,13 +4417,23 @@ Gid_t getegid (void);
 #  define DEBUG_q_TEST_ UNLIKELY(PL_debug & DEBUG_q_FLAG)
 #  define DEBUG_M_TEST_ UNLIKELY(PL_debug & DEBUG_M_FLAG)
 #  define DEBUG_B_TEST_ UNLIKELY(PL_debug & DEBUG_B_FLAG)
-#  define DEBUG_L_TEST_ UNLIKELY(PL_debug & DEBUG_L_FLAG)
+
+/* Locale initialization comes earlier than PL_debug gets set,
+ * DEBUG_LOCALE_INITIALIZATION_, if defined, will be set early enough */
+#  ifndef DEBUG_LOCALE_INITIALIZATION_
+#    define DEBUG_LOCALE_INITIALIZATION_ 0
+#  endif
+#  define DEBUG_L_TEST_                                                 \
+        (   UNLIKELY(DEBUG_LOCALE_INITIALIZATION_)                      \
+         || UNLIKELY(PL_debug & DEBUG_L_FLAG))
+#  define DEBUG_Lv_TEST_                                                \
+        (   UNLIKELY(DEBUG_LOCALE_INITIALIZATION_)                      \
+         || UNLIKELY(DEBUG_BOTH_FLAGS_TEST_(DEBUG_L_FLAG, DEBUG_v_FLAG)))
 #  define DEBUG_i_TEST_ UNLIKELY(PL_debug & DEBUG_i_FLAG)
 #  define DEBUG_y_TEST_ UNLIKELY(PL_debug & DEBUG_y_FLAG)
 #  define DEBUG_Xv_TEST_ DEBUG_BOTH_FLAGS_TEST_(DEBUG_X_FLAG, DEBUG_v_FLAG)
 #  define DEBUG_Uv_TEST_ DEBUG_BOTH_FLAGS_TEST_(DEBUG_U_FLAG, DEBUG_v_FLAG)
 #  define DEBUG_Pv_TEST_ DEBUG_BOTH_FLAGS_TEST_(DEBUG_P_FLAG, DEBUG_v_FLAG)
-#  define DEBUG_Lv_TEST_ DEBUG_BOTH_FLAGS_TEST_(DEBUG_L_FLAG, DEBUG_v_FLAG)
 #  define DEBUG_yv_TEST_ DEBUG_BOTH_FLAGS_TEST_(DEBUG_y_FLAG, DEBUG_v_FLAG)
 
 #ifdef DEBUGGING