diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 75efc4a62d1..4bc5f4f144c 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -8479,7 +8479,7 @@ gdb_caching_proc have_mpx {
     set status [lindex $result 0]
     set output [lindex $result 1]
     set status [expr ($status == 0) \
-		    && ![string equal $output "No MPX support\r\n"]]
+		    && ![regexp "^No MPX support\r\n" $output]]
 
     remote_file build delete $obj