diff --git a/ChangeLog b/ChangeLog
index 6fbe294b..c6883e57 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2006-03-17  Ralf Wildenhues  <Ralf.Wildenhues@gmx.de>
 
+	* lib/m4sugar/m4sh.m4 (_AS_DETECT_BETTER_SHELL): Prepend
+	the directory `/usr/bin/posix' in the shell search, to prefer
+	the Posix shell not only in subsequent spawns as with `$BIN_SH'
+	on Tru64.
+
 	* doc/autoconf.texi (contents): To fix texi2html output, hide
 	`@setcontentsaftertitlepage' for HTML.
 	(Writing Autoconf Macros): Likewise, insert space after `@c'.
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 3b96b6d3..d6e93ee6 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -226,7 +226,7 @@ if test "x$CONFIG_SHELL" = x; then
 	 _AS_RUN([_AS_DETECT_SUGGESTED_BODY]) 2> /dev/null],
     [],
     [as_candidate_shells=
-    _AS_PATH_WALK([/bin$PATH_SEPARATOR/usr/bin$PATH_SEPARATOR$PATH],
+    _AS_PATH_WALK([/usr/bin/posix$PATH_SEPARATOR/bin$PATH_SEPARATOR/usr/bin$PATH_SEPARATOR$PATH],
       [case $as_dir in
 	 /*)
 	   for as_base in sh bash ksh sh5; do