diff --git a/ANNOUNCE b/ANNOUNCE
index ad1205cab..1a31b0232 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -655,6 +655,8 @@ Version 1.7.0beta42 [November 17, 2014]
     macro definitions with ifndef guards (Cosmin).
   Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
   Removed the obsolete $ARCH variable from scripts/makefile.darwin.
+  Merged clang no-warning fix from libpng-1.6.13: png_digit was defined
+    but never used in pngerror.c.
 
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diff --git a/CHANGES b/CHANGES
index 756035c00..1c9dcf0fe 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4944,6 +4944,8 @@ Version 1.7.0beta42 [November 17, 2014]
     macro definitions with ifndef guards (Cosmin).
   Added "-D_CRT_SECURE_NO_WARNINGS" to CFLAGS in scripts/makefile.vcwin32.
   Removed the obsolete $ARCH variable from scripts/makefile.darwin.
+  Merged clang no-warning fix from libpng-1.6.13: png_digit was defined
+    but never used in pngerror.c.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/pngerror.c b/pngerror.c
index 0a33e8952..b66fc6aef 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -415,10 +415,13 @@ png_app_error(png_const_structrp png_ptr, png_const_charp error_message)
 }
 #endif /* BENIGN_ERRORS */
 
+#define PNG_MAX_ERROR_TEXT 196 /* Currently limited by profile_error in png.c */
+#if defined(PNG_WARNINGS_SUPPORTED) || \
+   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 /* These utilities are used internally to build an error message that relates
  * to the current chunk.  The chunk name comes from png_ptr->chunk_name,
- * this is used to prefix the message.  The message is limited in length
- * to 63 bytes, the name characters are output as hex digits wrapped in []
+ * which is used to prefix the message.  The message is limited in length
+ * to 63 bytes. The name characters are output as hex digits wrapped in []
  * if the character is invalid.
  */
 #define isnonalpha(c) ((c) < 65 || (c) > 122 || ((c) > 90 && (c) < 97))
@@ -427,9 +430,6 @@ static PNG_CONST char png_digit[16] = {
    'A', 'B', 'C', 'D', 'E', 'F'
 };
 
-#define PNG_MAX_ERROR_TEXT 196 /* Currently limited be profile_error in png.c */
-#if defined(PNG_WARNINGS_SUPPORTED) || \
-   (defined(PNG_READ_SUPPORTED) && defined(PNG_ERROR_TEXT_SUPPORTED))
 static void /* PRIVATE */
 png_format_buffer(png_const_structrp png_ptr, png_charp buffer, png_const_charp
     error_message)
@@ -969,5 +969,5 @@ png_safe_execute(png_imagep image_in, int (*function)(png_voidp), png_voidp arg)
 
    return result;
 }
-#endif /* SIMPLIFIED READ/WRITE */
+#endif /* SIMPLIFIED READ || SIMPLIFIED_WRITE */
 #endif /* READ || WRITE */