diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 6fcf81da03..44077d03eb 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2012-12-23  Pierre Muller  <muller@sourceware.org>
+
+        * gdbint.texinfo (Function prototypes): Require use of "extern"
+        modifier for function prototypes in headers.
+
 2012-12-19  Joel Brobecker  <brobecker@adacore.com>
 
 	* refcard.tex: Update copyright notice to GPL v3 or later.
diff --git a/gdb/doc/gdbint.texinfo b/gdb/doc/gdbint.texinfo
index bb7e5e570c..945431d4a8 100644
--- a/gdb/doc/gdbint.texinfo
+++ b/gdb/doc/gdbint.texinfo
@@ -5935,7 +5935,8 @@ argument type and name, with the name matching that used in the actual
 function definition.
 
 All external functions should have a declaration in a header file that
-callers include, except for @code{_initialize_*} functions, which must
+callers include, that declaration should use the @code{extern} modifier.
+The only exception concerns @code{_initialize_*} functions, which must
 be external so that @file{init.c} construction works, but shouldn't be
 visible to random source files.