diff --git a/src/osmo-bsc/osmo_bsc_filter.c b/src/osmo-bsc/osmo_bsc_filter.c
index 3b72aee..b4985f2 100644
--- a/src/osmo-bsc/osmo_bsc_filter.c
+++ b/src/osmo-bsc/osmo_bsc_filter.c
@@ -49,6 +49,11 @@
 	uint8_t tzbsd = 0;
 	uint8_t dst = 0;
 
+	/* Is TZ patching enabled? */
+	struct gsm_tz *tz = &conn->network->tz;
+	if (!tz->override)
+		return 0;
+
 	parse_res = tlv_parse(&tp, &gsm48_mm_att_tlvdef, data, length, 0, 0);
 	if (parse_res <= 0 && parse_res != -3)
 		/* FIXME: -3 means unknown IE error, so this accepts messages
@@ -56,11 +61,6 @@
 		 * IE and the message is broken or parsed incompletely. */
 		return 0;
 
-	/* Is TZ patching enabled? */
-	struct gsm_tz *tz = &conn->network->tz;
-	if (!tz->override)
-		return 0;
-
 	/* Convert tz.hr and tz.mn to units */
 	if (tz->hr < 0) {
 		tzunits = -tz->hr*4;