diff --git a/src/ChangeLog b/src/ChangeLog
index 54e5a39b21e..aaa200054c5 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2011-09-24  Glenn Morris  <rgm@gnu.org>
+
+	* minibuf.c (read_minibuf): Disable line truncation.  (Bug#5715)
+
 2011-09-24  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Fix minor problems found by static checking.
diff --git a/src/minibuf.c b/src/minibuf.c
index d3f43b06254..341d544ef51 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -559,6 +559,10 @@ read_minibuf (Lisp_Object map, Lisp_Object initial, Lisp_Object prompt,
   minibuffer = get_minibuffer (minibuf_level);
   Fset_buffer (minibuffer);
 
+  /* Defeat (setq-default truncate-lines t), since truncated lines do
+     not work correctly in minibuffers.  (Bug#5715, etc)  */
+  BVAR (current_buffer, truncate_lines) = Qnil;
+
   /* If appropriate, copy enable-multibyte-characters into the minibuffer.  */
   if (inherit_input_method)
     BVAR (current_buffer, enable_multibyte_characters) = enable_multibyte;