diff --git a/channels/misdn/isdn_lib.c b/channels/misdn/isdn_lib.c
index 4b4a96f8b9..a8d730e38e 100644
--- a/channels/misdn/isdn_lib.c
+++ b/channels/misdn/isdn_lib.c
@@ -3116,7 +3116,7 @@ struct misdn_bchannel *manager_find_bc_holded(struct misdn_bchannel* bc)
 
 
 
-int test_inuse(struct misdn_bchannel *bc)
+static int test_inuse(struct misdn_bchannel *bc)
 {
 	struct timeval now;
 	gettimeofday(&now, NULL);