diff --git a/src/ChangeLog b/src/ChangeLog
index 570a55ec2a2..3c6d4fc8841 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2011-04-10  Chong Yidong  <cyd@stupidchicken.com>
+
+	* buffer.c (syms_of_buffer): Doc fix (Bug#6902).
+
 2011-04-08  Chong Yidong  <cyd@stupidchicken.com>
 
 	* ftfont.c (get_adstyle_property, ftfont_pattern_entity): Use
diff --git a/src/buffer.c b/src/buffer.c
index e7759cb5255..076495cfc64 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5746,7 +5746,8 @@ Linefeed indents to this column in Fundamental mode.  */);
 
   DEFVAR_PER_BUFFER ("tab-width", &current_buffer->tab_width,
 		     make_number (LISP_INT_TAG),
-		     doc: /* *Distance between tab stops (for display of tab characters), in columns.  */);
+		     doc: /* *Distance between tab stops (for display of tab characters), in columns.
+This should be an integer greater than zero.  */);
 
   DEFVAR_PER_BUFFER ("ctl-arrow", &current_buffer->ctl_arrow, Qnil,
 		     doc: /* *Non-nil means display control chars with uparrow.