Index: res/res_musiconhold.c
===================================================================
--- res/res_musiconhold.c	(revision 226780)
+++ res/res_musiconhold.c	(working copy)
@@ -1368,9 +1368,20 @@
 {
 	struct mohclass *class = obj;
 	struct mohdata *member;
+	pthread_t tid = 0;
 
 	ast_debug(1, "Destroying MOH class '%s'\n", class->name);
 
+	/* Kill the thread first, so it cannot restart the child process while the
+	 * class is being destroyed */
+	if (class->thread > 0) {
+		tid = class->thread;
+		class->thread = AST_PTHREADT_NULL;
+		pthread_cancel(tid);
+		/* We'll collect the exit status later, after we ensure all the readers
+		 * are dead. */
+	}
+
 	if (class->pid > 1) {
 		char buff[8192];
 		int bytes, tbytes = 0, stime = 0, pid = 0;
@@ -1404,12 +1415,6 @@
 		free(member);
 	}
 
-	if (class->thread) {
-		pthread_cancel(class->thread);
-		pthread_join(class->thread, NULL);
-		class->thread = AST_PTHREADT_NULL;
-	}
-
 	if (class->filearray) {
 		int i;
 		for (i = 0; i < class->total_files; i++) {
@@ -1418,6 +1423,11 @@
 		free(class->filearray);
 		class->filearray = NULL;
 	}
+
+	/* Finally, collect the exit status of the monitor thread */
+	if (tid > 0) {
+		pthread_join(tid, NULL);
+	}
 }
 
 static int moh_class_mark(void *obj, void *arg, int flags)