diff --git a/src/ChangeLog b/src/ChangeLog
index 001819a32a8..e04746694f1 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,7 @@
+2008-01-16  Glenn Morris  <rgm@gnu.org>
+
+	* coding.c (select-safe-coding-system-function): Doc fix.
+
 2008-01-15  Glenn Morris  <rgm@gnu.org>
 
 	* config.in: Revert 2008-01-13 change: this is a generated file.
diff --git a/src/coding.c b/src/coding.c
index dda3f0f854c..7bfec68d5d1 100644
--- a/src/coding.c
+++ b/src/coding.c
@@ -8157,7 +8157,9 @@ Only 128th through 159th elements has a meaning.  */);
 
 If set, this function is called to force a user to select a proper
 coding system which can encode the text in the case that a default
-coding system used in each operation can't encode the text.
+coding system used in each operation can't encode the text.  The
+function should take care that the buffer is not modified while
+the coding system is being selected.
 
 The default value is `select-safe-coding-system' (which see).  */);
   Vselect_safe_coding_system_function = Qnil;