diff --git a/pngconf.h b/pngconf.h
index f1235a6..c4c4ffa 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1534,18 +1534,17 @@
  * functions in png.h will generate compiler warnings.  Added at libpng
  * version 1.2.41.
  */
-#ifdef __GNUC__
-#  ifndef PNG_USE_RESULT
-#    define PNG_USE_RESULT __attribute__((__warn_unused_result__))
-#  endif
-#  ifndef PNG_NORETURN
-#    define PNG_NORETURN   __attribute__((__noreturn__))
-#  endif
-#  ifndef PNG_ALLOCATED
-#    define PNG_ALLOCATED  __attribute__((__malloc__))
-#  endif
+#  ifdef __GNUC__
+#    ifndef PNG_USE_RESULT
+#      define PNG_USE_RESULT __attribute__((__warn_unused_result__))
+#    endif
+#    ifndef PNG_NORETURN
+#      define PNG_NORETURN   __attribute__((__noreturn__))
+#    endif
+#    ifndef PNG_ALLOCATED
+#      define PNG_ALLOCATED  __attribute__((__malloc__))
+#    endif
 
-#  ifndef PNG_CONFIGURE_LIBPNG
     /* This specifically protects structure members that should only be
      * accessed from within the library, therefore should be empty during
      * a library build.
@@ -1557,16 +1556,15 @@
 #      define PNG_DEPSTRUCT  __attribute__((__deprecated__))
 #    endif
 #    ifndef PNG_PRIVATE
-#if 0 /* Doesn't work so we use deprecated instead*/
-#      define PNG_PRIVATE \
-        __attribute__((warning("This function is not exported by libpng.")))
-#else
-#      define PNG_PRIVATE \
-        __attribute__((__deprecated__))
-#endif
-#    endif
-#  endif
-#endif
+#      if 0 /* Doesn't work so we use deprecated instead*/
+#        define PNG_PRIVATE \
+          __attribute__((warning("This function is not exported by libpng.")))
+#      else
+#        define PNG_PRIVATE \
+          __attribute__((__deprecated__))
+#      endif
+#    endif /* PNG_PRIVATE */
+#  endif /* __GNUC__ */
 #endif /* PNG_PEDANTIC_WARNINGS */
 
 #ifndef PNG_DEPRECATED