diff --git a/vp9/encoder/vp9_bitstream.c b/vp9/encoder/vp9_bitstream.c
index d638a21461981820407f6fac7062f51a80d56801..b0ff0fa81a14f7abfed125f747d441ed6a738d52 100644
--- a/vp9/encoder/vp9_bitstream.c
+++ b/vp9/encoder/vp9_bitstream.c
@@ -1216,7 +1216,7 @@ void vp9_pack_bitstream(VP9_COMP *cpi, uint8_t *dest, size_t *size) {
   saved_wb = wb;
   vp9_wb_write_literal(&wb, 0, 16);  // don't know in advance first part. size
 
-  uncompressed_hdr_size = vp9_rb_bytes_written(&wb);
+  uncompressed_hdr_size = vp9_wb_bytes_written(&wb);
   data += uncompressed_hdr_size;
 
   vp9_clear_system_state();
diff --git a/vp9/encoder/vp9_write_bit_buffer.c b/vp9/encoder/vp9_write_bit_buffer.c
index 962d0ca5645f382770c091e9aa82ea9ca68a726f..6d55e84e869c9720eac9a20f84e2c5e74ad88373 100644
--- a/vp9/encoder/vp9_write_bit_buffer.c
+++ b/vp9/encoder/vp9_write_bit_buffer.c
@@ -8,9 +8,10 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <limits.h>
 #include "vp9/encoder/vp9_write_bit_buffer.h"
 
-size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb) {
+size_t vp9_wb_bytes_written(const struct vp9_write_bit_buffer *wb) {
   return wb->bit_offset / CHAR_BIT + (wb->bit_offset % CHAR_BIT > 0);
 }
 
diff --git a/vp9/encoder/vp9_write_bit_buffer.h b/vp9/encoder/vp9_write_bit_buffer.h
index 073608d7f9fbc67a3dacf8305131d15042ea4c82..59f9bbe30f3f9d9dd6d38dfda29d18feec0ec99c 100644
--- a/vp9/encoder/vp9_write_bit_buffer.h
+++ b/vp9/encoder/vp9_write_bit_buffer.h
@@ -11,8 +11,6 @@
 #ifndef VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_
 #define VP9_ENCODER_VP9_WRITE_BIT_BUFFER_H_
 
-#include <limits.h>
-
 #include "vpx/vpx_integer.h"
 
 #ifdef __cplusplus
@@ -24,7 +22,7 @@ struct vp9_write_bit_buffer {
   size_t bit_offset;
 };
 
-size_t vp9_rb_bytes_written(struct vp9_write_bit_buffer *wb);
+size_t vp9_wb_bytes_written(const struct vp9_write_bit_buffer *wb);
 
 void vp9_wb_write_bit(struct vp9_write_bit_buffer *wb, int bit);