diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index e2594c69735..518118ce5d1 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-02-17  Pedro Alves  <pedro@codesourcery.com>
+
+	* lib/gdb.exp (build_id_debug_filename_get): Don't assume new
+	`regsub' syntax available.
+
 2010-02-17  Pedro Alves  <pedro@codesourcery.com>
 
 	* gdb.base/shmain.c (main): Remove printf call.
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index a42d5517f60..627941d6d1e 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -2830,7 +2830,7 @@ proc build_id_debug_filename_get { exec } {
     }
     # Convert it to hex.
     binary scan $data H* data
-    set data [regsub {^..} $data {\0/}]
+    regsub {^..} $data {\0/} data
     return ".build-id/${data}.debug";
 }