diff --git a/src/buffer.c b/src/buffer.c
index 69bf17283ee..68013d4032a 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -373,7 +373,7 @@ The value is never nil.")
   b->newline_cache = 0;
   b->width_run_cache = 0;
   b->width_table = Qnil;
-  b->minibuffer_prompt_length = Qnil;
+  b->prompt_end_charpos = Qnil;
   b->prevent_redisplay_optimizations_p = 1;
 
   /* Put this on the chain of all buffers including killed ones.  */
@@ -453,7 +453,7 @@ NAME should be a string which is not the name of an existing buffer.")
   b->newline_cache = 0;
   b->width_run_cache = 0;
   b->width_table = Qnil;
-  b->minibuffer_prompt_length = Qnil;
+  b->prompt_end_charpos = Qnil;
 
   /* Put this on the chain of all buffers including killed ones.  */
   b->next = all_buffers;
@@ -1223,7 +1223,7 @@ with SIGHUP.")
       b->width_run_cache = 0;
     }
   b->width_table = Qnil;
-  b->minibuffer_prompt_length = Qnil;
+  b->prompt_end_charpos = Qnil;
   UNBLOCK_INPUT;
   b->undo_list = Qnil;
 
@@ -1706,8 +1706,8 @@ so the buffer is truly empty after this.")
 {
   Fwiden ();
   
-  if (INTEGERP (current_buffer->minibuffer_prompt_length))
-    del_range (XINT (current_buffer->minibuffer_prompt_length), Z);
+  if (INTEGERP (current_buffer->prompt_end_charpos))
+    del_range (XINT (current_buffer->prompt_end_charpos), Z);
   else
     del_range (BEG, Z);