diff --git a/pngerror.c b/pngerror.c
index e0585a856..547d08979 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -161,7 +161,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02u:
             /* Expects at least 2 digits. */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_u:
             *--end = digits[number % 10];
@@ -171,7 +171,7 @@ png_format_number(png_const_charp start, png_charp end, int format,
          case PNG_NUMBER_FORMAT_02x:
             /* This format expects at least two digits */
             mincount = 2;
-            /* fall through */
+            /* FALL THROUGH */
 
          case PNG_NUMBER_FORMAT_x:
             *--end = digits[number & 0xf];
diff --git a/pngrtran.c b/pngrtran.c
index 66dc808f4..11a0bfe67 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1221,7 +1221,7 @@ png_init_rgb_transformations(png_structp png_ptr)
             default:
 
             case 8:
-               /* Already 8 bits, fall through */
+               /* FALL THROUGH (already 8 bits) */
 
             case 16:
                /* Already a full 16 bits */