diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index fd0f95988c..d85559551f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-14  Tom Tromey  <tom@tromey.com>
+
+	* valprint.c (print_octal_chars): Use HOST_CHAR_BIT.
+	(print_binary_chars): Likewise.
+	(BITS_IN_BYTES): Remove.
+
 2017-08-14  Tom Tromey  <tom@tromey.com>
 
 	PR gdb/21675
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 9e216cff92..eef99b1f3b 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -1490,9 +1490,6 @@ void
 print_binary_chars (struct ui_file *stream, const gdb_byte *valaddr,
 		    unsigned len, enum bfd_endian byte_order, bool zero_pad)
 {
-
-#define BITS_IN_BYTES 8
-
   const gdb_byte *p;
   unsigned int i;
   int b;
@@ -1512,7 +1509,7 @@ print_binary_chars (struct ui_file *stream, const gdb_byte *valaddr,
 	  /* Every byte has 8 binary characters; peel off
 	     and print from the MSB end.  */
 
-	  for (i = 0; i < (BITS_IN_BYTES * sizeof (*p)); i++)
+	  for (i = 0; i < (HOST_CHAR_BIT * sizeof (*p)); i++)
 	    {
 	      if (*p & (mask >> i))
 		b = '1';
@@ -1532,7 +1529,7 @@ print_binary_chars (struct ui_file *stream, const gdb_byte *valaddr,
 	   p >= valaddr;
 	   p--)
 	{
-	  for (i = 0; i < (BITS_IN_BYTES * sizeof (*p)); i++)
+	  for (i = 0; i < (HOST_CHAR_BIT * sizeof (*p)); i++)
 	    {
 	      if (*p & (mask >> i))
 		b = '1';
@@ -1612,7 +1609,7 @@ print_octal_chars (struct ui_file *stream, const gdb_byte *valaddr,
   /* For 32 we start in cycle 2, with two bits and one bit carry;
      for 64 in cycle in cycle 1, with one bit and a two bit carry.  */
 
-  cycle = (len * BITS_IN_BYTES) % BITS_IN_OCTAL;
+  cycle = (len * HOST_CHAR_BIT) % BITS_IN_OCTAL;
   carry = 0;
 
   fputs_filtered ("0", stream);