fix confusing typo in constant (THAN -> THEN)
diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c
index 1a1d6f2..1524ec4 100644
--- a/openbsc/src/libmsc/gsm_04_08.c
+++ b/openbsc/src/libmsc/gsm_04_08.c
@@ -231,7 +231,7 @@
 		/* FIXME: Should start a timer for completion ... */
 
 	/* Then do whatever is needed ... */
-	if (rc == AUTH_DO_AUTH_THAN_CIPH) {
+	if (rc == AUTH_DO_AUTH_THEN_CIPH) {
 		/* Start authentication */
 		return gsm48_tx_mm_auth_req(conn, op->atuple.rand, op->atuple.key_seq);
 	} else if (rc == AUTH_DO_CIPH) {