diff --git a/openbsc/src/gprs/sgsn_auth.c b/openbsc/src/gprs/sgsn_auth.c
index 4b69a0d..1fa7fc4 100644
--- a/openbsc/src/gprs/sgsn_auth.c
+++ b/openbsc/src/gprs/sgsn_auth.c
@@ -20,6 +20,7 @@
  */
 
 #include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
+#include <osmocom/core/utils.h>
 #include <openbsc/sgsn.h>
 #include <openbsc/gprs_sgsn.h>
 #include <openbsc/gprs_gmm.h>
@@ -62,7 +63,7 @@
 	acl = talloc_zero(NULL, struct imsi_acl_entry);
 	if (!acl)
 		return -ENOMEM;
-	strncpy(acl->imsi, imsi, sizeof(acl->imsi) - 1);
+	osmo_strlcpy(acl->imsi, imsi, sizeof(acl->imsi));
 
 	llist_add(&acl->list, &cfg->imsi_acl);