diff --git a/main/channel.c b/main/channel.c
index a57f64925d..654f82419c 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -2233,6 +2233,7 @@ int ast_settimeout(struct ast_channel *c, int samples, int (*func)(const void *d
 {
 	int res = -1;
 #ifdef HAVE_DAHDI
+	ast_channel_lock(c);
 	if (c->timingfd > -1) {
 		if (!func) {
 			samples = 0;
@@ -2243,7 +2244,8 @@ int ast_settimeout(struct ast_channel *c, int samples, int (*func)(const void *d
 		c->timingfunc = func;
 		c->timingdata = data;
 	}
-#endif	
+	ast_channel_unlock(c);
+#endif
 	return res;
 }