diff --git a/src/hb-private.hh b/src/hb-private.hh
index a82773fba..535ea3a28 100644
--- a/src/hb-private.hh
+++ b/src/hb-private.hh
@@ -501,7 +501,7 @@ _hb_debug (unsigned int level,
 #define DEBUG_LEVEL(WHAT, LEVEL) (_hb_debug ((LEVEL), HB_DEBUG_##WHAT))
 #define DEBUG(WHAT) (DEBUG_LEVEL (WHAT, 0))
 
-template <int max_level> inline bool /* always returns TRUE */
+template <int max_level> inline void
 _hb_debug_msg_va (const char *what,
 		  const void *obj,
 		  const char *func,
@@ -512,7 +512,7 @@ _hb_debug_msg_va (const char *what,
 		  va_list ap)
 {
   if (!_hb_debug (level, max_level))
-    return TRUE;
+    return;
 
   static const char bars[] = "││││││││││││││││││││││││││││││││││││││││";
 
@@ -538,10 +538,8 @@ _hb_debug_msg_va (const char *what,
     vfprintf (stderr, message, ap);
 
   fprintf (stderr, "\n");
-
-  return TRUE;
 }
-template <> inline bool /* always returns TRUE */
+template <> inline void
 _hb_debug_msg_va<0> (const char *what,
 		     const void *obj,
 		     const char *func,
@@ -549,12 +547,9 @@ _hb_debug_msg_va<0> (const char *what,
 		     unsigned int level,
 		     int level_dir,
 		     const char *message,
-		     va_list ap)
-{
-  return TRUE;
-}
+		     va_list ap) {}
 
-template <int max_level> inline bool /* always returns TRUE */
+template <int max_level> inline void
 _hb_debug_msg (const char *what,
 	       const void *obj,
 	       const char *func,
@@ -563,7 +558,7 @@ _hb_debug_msg (const char *what,
 	       int level_dir,
 	       const char *message,
 	       ...) HB_PRINTF_FUNC(7, 8);
-template <int max_level> inline bool /* always returns TRUE */
+template <int max_level> inline void
 _hb_debug_msg (const char *what,
 	       const void *obj,
 	       const char *func,
@@ -575,14 +570,10 @@ _hb_debug_msg (const char *what,
 {
   va_list ap;
   va_start (ap, message);
-
-  bool ret = _hb_debug_msg_va<max_level> (what, obj, func, indented, level, level_dir, message, ap);
-
+  _hb_debug_msg_va<max_level> (what, obj, func, indented, level, level_dir, message, ap);
   va_end (ap);
-
-  return ret;
 }
-template <> inline bool /* always returns TRUE */
+template <> inline void
 _hb_debug_msg<0> (const char *what,
 		  const void *obj,
 		  const char *func,
@@ -591,7 +582,7 @@ _hb_debug_msg<0> (const char *what,
 		  int level_dir,
 		  const char *message,
 		  ...) HB_PRINTF_FUNC(7, 8);
-template <> inline bool /* always returns TRUE */
+template <> inline void
 _hb_debug_msg<0> (const char *what,
 		  const void *obj,
 		  const char *func,
@@ -599,10 +590,7 @@ _hb_debug_msg<0> (const char *what,
 		  unsigned int level,
 		  int level_dir,
 		  const char *message,
-		  ...)
-{
-  return TRUE;
-}
+		  ...) {}
 
 #define DEBUG_MSG_LEVEL(WHAT, OBJ, LEVEL, LEVEL_DIR, ...)	_hb_debug_msg<HB_DEBUG_##WHAT> (#WHAT, (OBJ), NULL,    TRUE, (LEVEL), (LEVEL_DIR), __VA_ARGS__)
 #define DEBUG_MSG(WHAT, OBJ, ...) 				_hb_debug_msg<HB_DEBUG_##WHAT> (#WHAT, (OBJ), NULL,    FALSE, 0, 0, __VA_ARGS__)