diff --git a/contrib/pngminim/decoder/pngusr.h b/contrib/pngminim/decoder/pngusr.h
index 9cbfc5361..6e40d6498 100644
--- a/contrib/pngminim/decoder/pngusr.h
+++ b/contrib/pngminim/decoder/pngusr.h
@@ -25,7 +25,7 @@
 
 #define PNG_NO_READ_GAMMA
 #define PNG_NO_READ_BACKGROUND
-#define PNG_NO_READ_DITHER
+#define PNG_NO_READ_QUANTIZE
 #define PNG_NO_READ_INVERT
 #define PNG_NO_READ_SHIFT
 #define PNG_NO_READ_PACK
diff --git a/contrib/pngminim/encoder/pngusr.h b/contrib/pngminim/encoder/pngusr.h
index 2feed2ee5..02eeaa8c7 100644
--- a/contrib/pngminim/encoder/pngusr.h
+++ b/contrib/pngminim/encoder/pngusr.h
@@ -23,7 +23,7 @@
 
 #define PNG_NO_WRITE_BACKGROUND
 #define PNG_NO_WRITE_GAMMA
-#define PNG_NO_WRITE_DITHER
+#define PNG_NO_WRITE_QUANTIZE
 #define PNG_NO_WRITE_INVERT
 #define PNG_NO_WRITE_SHIFT
 #define PNG_NO_WRITE_PACK
diff --git a/pngconf.h b/pngconf.h
index d6669f2e3..6a2de36ac 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -515,7 +515,9 @@
 #  endif
 #  ifndef PNG_NO_READ_QUANTIZE
      /* Prior to libpng-1.4.0 this was PNG_READ_DITHER_SUPPORTED */
-#    define PNG_READ_QUANTIZE_SUPPORTED
+#    ifndef PNG_NO_READ_DITHER  /* This migration aid will be removed */
+#      define PNG_READ_QUANTIZE_SUPPORTED
+#    endif
 #  endif
 #  ifndef PNG_NO_READ_BACKGROUND
 #    define PNG_READ_BACKGROUND_SUPPORTED