diff --git a/pngread.c b/pngread.c
index b11f4db0f..ba56032e0 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1286,24 +1286,26 @@ png_read_png(png_structp png_ptr, png_infop info_ptr,
 
    /* -------------- image transformations start here ------------------- */
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
+#ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
    /* Tell libpng to strip 16-bit/color files down to 8 bits per color.
     */
-#  ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
    if (transforms & PNG_TRANSFORM_SCALE_16)
-      png_set_scale_16(png_ptr);
-#    ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
-   else
-
-#    endif
-#  endif
-#  ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   {
      /* Added at libpng-1.5.4. "strip_16" produces the same result that it
       * did in earlier versions, while "scale_16" is now more accurate.
       */
+      png_set_scale_16(png_ptr);
+   }
+
+#  ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
+   else
+#  endif
+
+#endif
+
+#ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED
      if (transforms & PNG_TRANSFORM_STRIP_16)
         png_set_strip_16(png_ptr);
-#  endif
 #endif
 
 #ifdef PNG_READ_STRIP_ALPHA_SUPPORTED
diff --git a/pngrtran.c b/pngrtran.c
index 0fca5dd51..e4ed0b996 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1873,23 +1873,24 @@ png_read_transform_info(png_structp png_ptr, png_infop info_ptr)
 #endif
 
 #ifdef PNG_READ_16_TO_8_SUPPORTED
-#ifdef PNG_READ_16BIT_SUPPORTED
+#  ifdef PNG_READ_16BIT_SUPPORTED
    if ((png_ptr->transformations & (PNG_16_TO_8 | PNG_SCALE_16_TO_8)) &&
        (info_ptr->bit_depth == 16))
       info_ptr->bit_depth = 8;
-#else
+#  else
+
    /* Force chopping 16-bit input down to 8 */
    if (info_ptr->bit_depth == 16)
    {
-      if (!(png_ptr->transformations & PNG_SCALE_16_TO_8))
-#if PNG_READ_STRIP_16_TO_8_SUPPORTED
+      if (!(png_ptr->transformations & PNG_16_TO_8))
+#    if PNG_READ_STRIP_16_TO_8_SUPPORTED
         png_ptr->transformations |=PNG_16_TO_8;
-#else
+#    else
         png_ptr->transformations |=PNG_SCALE_16_TO_8;
-#endif
+#    endif
       info_ptr->bit_depth = 8;
    }
-#endif
+#  endif
 #endif
 
 #ifdef PNG_READ_GRAY_TO_RGB_SUPPORTED
@@ -2151,7 +2152,7 @@ png_do_read_transformations(png_structp png_ptr)
 #endif
 
 #ifdef PNG_READ_SCALE_16_TO_8_SUPPORTED
-   if (png_ptr->transformations & PNG_16_TO_8)
+   if (png_ptr->transformations & PNG_SCALE_16_TO_8)
       png_do_scale_16_to_8(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 #ifdef PNG_READ_STRIP_16_TO_8_SUPPORTED