diff --git a/openbsc/src/libbsc/gsm_subscriber_base.c b/openbsc/src/libbsc/gsm_subscriber_base.c
index 747a699..5755687 100644
--- a/openbsc/src/libbsc/gsm_subscriber_base.c
+++ b/openbsc/src/libbsc/gsm_subscriber_base.c
@@ -104,7 +104,8 @@
 	if (!subscr)
 		return NULL;
 
-	strcpy(subscr->imsi, imsi);
+	strncpy(subscr->imsi, imsi, GSM_IMSI_LENGTH);
+	subscr->imsi[GSM_IMSI_LENGTH - 1] = '\0';
 	subscr->net = net;
 	return subscr;
 }