Index: res/res_musiconhold.c
===================================================================
--- res/res_musiconhold.c       (revision 30603)
+++ res/res_musiconhold.c       (working copy)
@@ -543,8 +543,8 @@
                                ast_log(LOG_DEBUG, "Read %d bytes of audio while expecting %d\n", res2, len);
                        continue;
                }
+               ast_mutex_lock(&moh_lock);
                pthread_testcancel();
-               ast_mutex_lock(&moh_lock);
                moh = class->members;
                while (moh) {
                        /* Write data */