diff --git a/ChangeLog b/ChangeLog
index 123cd441386..758817056af 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-04-18  Paolo Bonzini  <bonzini@gnu.org>
+
+	PR bootstrap/35457
+	* configure.ac: Include override.m4.
+	* configure: Regenerate.
+
 2008-04-18  Paolo Bonzini  <bonzini@gnu.org>
 
         * Makefile.tpl (restrap): Call `make all' using double-colon rules.
diff --git a/configure b/configure
index efcf6a7ce11..91ffd7f35a5 100755
--- a/configure
+++ b/configure
@@ -1415,13 +1415,22 @@ echo "$as_me: error: \`$ac_var' was not set in the previous run" >&2;}
     ,);;
     *)
       if test "x$ac_old_val" != "x$ac_new_val"; then
-	{ echo "$as_me:$LINENO: error: \`$ac_var' has changed since the previous run:" >&5
+        # differences in whitespace do not lead to failure.
+        ac_old_val_w=`echo x $ac_old_val`
+        ac_new_val_w=`echo x $ac_new_val`
+        if test "$ac_old_val_w" != "$ac_new_val_w"; then
+          { echo "$as_me:$LINENO: error: \`$ac_var' has changed since the previous run:" >&5
 echo "$as_me: error: \`$ac_var' has changed since the previous run:" >&2;}
-	{ echo "$as_me:$LINENO:   former value:  $ac_old_val" >&5
-echo "$as_me:   former value:  $ac_old_val" >&2;}
-	{ echo "$as_me:$LINENO:   current value: $ac_new_val" >&5
-echo "$as_me:   current value: $ac_new_val" >&2;}
-	ac_cache_corrupted=:
+          ac_cache_corrupted=:
+        else
+          { echo "$as_me:$LINENO: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&5
+echo "$as_me: warning: ignoring whitespace changes in \`$ac_var' since the previous run:" >&2;}
+          eval $ac_var=\$ac_old_val
+        fi
+        { echo "$as_me:$LINENO:   former value:  \`$ac_old_val'" >&5
+echo "$as_me:   former value:  \`$ac_old_val'" >&2;}
+        { echo "$as_me:$LINENO:   current value: \`$ac_new_val'" >&5
+echo "$as_me:   current value: \`$ac_new_val'" >&2;}
       fi;;
   esac
   # Pass precious variables to config.status.
diff --git a/configure.ac b/configure.ac
index ccb6240185b..c96f630d32b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,8 @@
 ##############################################################################
 ### WARNING: this file contains embedded tabs.  Do not run untabify on this file.
 
-sinclude(config/acx.m4)
+m4_include(config/acx.m4)
+m4_include(config/override.m4)
 m4_include(config/proginstall.m4)
 
 AC_INIT(move-if-change)