diff --git a/tests/auc/auc_test.c b/tests/auc/auc_test.c
index e507c29..f047a97 100644
--- a/tests/auc/auc_test.c
+++ b/tests/auc/auc_test.c
@@ -194,7 +194,7 @@
 	aud3g = (struct osmo_sub_auth_data){
 		.type = OSMO_AUTH_TYPE_UMTS,
 		.algo = OSMO_AUTH_ALG_MILENAGE,
-		.u.umts.sqn = 32,
+		.u.umts.sqn = 31,
 	};
 
 	osmo_hexparse("EB215756028D60E3275E613320AEC880",
@@ -204,10 +204,10 @@
 	next_rand("39fa2f4e3d523d8619a73b4f65c3e14d", true);
 
 	vec = (struct osmo_auth_vector){ {0} };
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
 	rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, NULL, NULL);
 	VERBOSE_ASSERT(rc, == 1, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 33, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
 
 	VEC_IS(&vec,
 	       "  rand: 39fa2f4e3d523d8619a73b4f65c3e14d\n"
@@ -223,11 +223,11 @@
 
 	/* even though vec is not zero-initialized, it should produce the same
 	 * result with the same sequence nr */
-	aud3g.u.umts.sqn = 32;
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	aud3g.u.umts.sqn = 31;
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
 	rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, NULL, NULL);
 	VERBOSE_ASSERT(rc, == 1, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 33, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
 
 	VEC_IS(&vec,
 	       "  rand: 39fa2f4e3d523d8619a73b4f65c3e14d\n"
@@ -301,7 +301,7 @@
 	aud3g = (struct osmo_sub_auth_data){
 		.type = OSMO_AUTH_TYPE_UMTS,
 		.algo = OSMO_AUTH_ALG_MILENAGE,
-		.u.umts.sqn = 32,
+		.u.umts.sqn = 31,
 	};
 
 	osmo_hexparse("EB215756028D60E3275E613320AEC880",
@@ -311,10 +311,10 @@
 	next_rand("39fa2f4e3d523d8619a73b4f65c3e14d", true);
 
 	vec = (struct osmo_auth_vector){ {0} };
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
 	rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, NULL, NULL);
 	VERBOSE_ASSERT(rc, == 1, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 33, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
 
 	VEC_IS(&vec,
 	       "  rand: 39fa2f4e3d523d8619a73b4f65c3e14d\n"
@@ -340,11 +340,11 @@
 
 	/* even though vec is not zero-initialized, it should produce the same
 	 * result with the same sequence nr */
-	aud3g.u.umts.sqn = 32;
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	aud3g.u.umts.sqn = 31;
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
 	rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, NULL, NULL);
 	VERBOSE_ASSERT(rc, == 1, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 33, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
 
 	VEC_IS(&vec,
 	       "  rand: 39fa2f4e3d523d8619a73b4f65c3e14d\n"
@@ -361,8 +361,8 @@
 
 	fprintf(stderr, "- test AUTS resync\n");
 	vec = (struct osmo_auth_vector){};
-	aud3g.u.umts.sqn = 32;
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	aud3g.u.umts.sqn = 31;
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
 
 	/* The AUTN sent was 8704f5ba55f30000d2ee44b22c8ea919
 	 * with the first 6 bytes being SQN ^ AK.
@@ -409,9 +409,8 @@
 	next_rand("897210a0f7de278f0b8213098e098a3f", true);
 	rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, rand_auts, auts);
 	VERBOSE_ASSERT(rc, == 1, "%d");
-	/* The USIM's last sqn was 23, the calculated vector was 24, hence the
-	 * next one stored should be 25. */
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 25, "%"PRIu64);
+	/* The USIM's last sqn was 23, the calculated vector was 24 */
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 24, "%"PRIu64);
 
 	VEC_IS(&vec,
 	       "  rand: 897210a0f7de278f0b8213098e098a3f\n"
@@ -428,19 +427,19 @@
 
 	fprintf(stderr, "- verify N vectors with AUTS resync"
 		" == N vectors without AUTS\n"
-		"First just set rand and sqn = 24, and compute 3 vectors\n");
+		"First just set rand and sqn = 23, and compute 3 vectors\n");
 	next_rand("897210a0f7de278f0b8213098e098a3f", false);
-	aud3g.u.umts.sqn = 24;
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 24, "%"PRIu64);
+	aud3g.u.umts.sqn = 23;
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 23, "%"PRIu64);
 
 	memset(vecs, 0, sizeof(vecs));
 	rc = auc_compute_vectors(vecs, 3, &aud2g, &aud3g, NULL, NULL);
 	VERBOSE_ASSERT(rc, == 3, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 27, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 26, "%"PRIu64);
 
 	_test_gen_vectors_3g_only__expect_vecs(vecs);
 
-	fprintf(stderr, "Now reach sqn = 24 with AUTS and expect the same\n");
+	fprintf(stderr, "Now reach sqn = 23 with AUTS and expect the same\n");
 	/* AUTS response by USIM */
 	osmo_hexparse("979498b1f72d3e28c59fa2e72f9c",
 		      auts, sizeof(auts));
diff --git a/tests/auc/auc_test.err b/tests/auc/auc_test.err
index 51f176c..bfc046f 100644
--- a/tests/auc/auc_test.err
+++ b/tests/auc/auc_test.err
@@ -22,13 +22,13 @@
 
 
 ===== test_gen_vectors_2g_plus_3g
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G + separate 2G
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC 2G: ki = eb215756028d60e3275e613320aec880
 DAUC vector [0]: rand = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 8704f5ba55d30000541dde77ea5b1d8c
 DAUC vector [0]: ck = f64735036e5871319c679f4742a75ea1
 DAUC vector [0]: ik = 27497388b6cb044648f396aa155b95ef
@@ -39,15 +39,15 @@
 DAUC vector [0]: sres = 429d5b27
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G + separate 2G
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC 2G: ki = eb215756028d60e3275e613320aec880
 DAUC vector [0]: rand = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 8704f5ba55d30000541dde77ea5b1d8c
 DAUC vector [0]: ck = f64735036e5871319c679f4742a75ea1
 DAUC vector [0]: ik = 27497388b6cb044648f396aa155b95ef
@@ -58,18 +58,18 @@
 DAUC vector [0]: sres = 429d5b27
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_gen_vectors_2g_plus_3g: SUCCESS
 
 
 ===== test_gen_vectors_3g_only
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC vector [0]: rand = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 8704f5ba55d30000541dde77ea5b1d8c
 DAUC vector [0]: ck = f64735036e5871319c679f4742a75ea1
 DAUC vector [0]: ik = 27497388b6cb044648f396aa155b95ef
@@ -79,14 +79,14 @@
 DAUC vector [0]: sres = 9b36efdf
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC vector [0]: rand = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 8704f5ba55d30000541dde77ea5b1d8c
 DAUC vector [0]: ck = f64735036e5871319c679f4742a75ea1
 DAUC vector [0]: ik = 27497388b6cb044648f396aa155b95ef
@@ -96,17 +96,17 @@
 DAUC vector [0]: sres = 9b36efdf
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 - test AUTS resync
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys), with AUTS resync
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC vector [0]: rand = 897210a0f7de278f0b8213098e098a3f
 DAUC vector [0]: resync: auts = 979498b1f72d3e28c59fa2e72f9c
 DAUC vector [0]: resync: rand_auts = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: resync: sqn = 24
+DAUC vector [0]: resync: sqn = 23
 DAUC vector [0]: autn = c6b9790dad4b00000cf322869ea6a481
 DAUC vector [0]: ck = e9922bd036718ed9e40bd1d02c3b81a5
 DAUC vector [0]: ik = f19c20ca863137f8892326d959ec5e01
@@ -116,16 +116,16 @@
 DAUC vector [0]: sres = 0ad888ef
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 25
+aud3g.u.umts.sqn == 24
 vector matches expectations
 - verify N vectors with AUTS resync == N vectors without AUTS
-First just set rand and sqn = 24, and compute 3 vectors
-aud3g.u.umts.sqn == 24
+First just set rand and sqn = 23, and compute 3 vectors
+aud3g.u.umts.sqn == 23
 DAUC Computing 3 auth vectors: 3G only (2G derived from 3G keys)
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC vector [0]: rand = 897210a0f7de278f0b8213098e098a3f
-DAUC vector [0]: sqn = 24
+DAUC vector [0]: sqn = 23
 DAUC vector [0]: autn = c6b9790dad4b00000cf322869ea6a481
 DAUC vector [0]: ck = e9922bd036718ed9e40bd1d02c3b81a5
 DAUC vector [0]: ik = f19c20ca863137f8892326d959ec5e01
@@ -135,7 +135,7 @@
 DAUC vector [0]: sres = 0ad888ef
 DAUC vector [0]: auth_types = 0x3
 DAUC vector [1]: rand = 9a8321b108ef38a01c93241a9f1a9b50
-DAUC vector [1]: sqn = 25
+DAUC vector [1]: sqn = 24
 DAUC vector [1]: autn = 79a5113eb0910000be6020540503ffc5
 DAUC vector [1]: ck = 3686f05df057d1899c66ae4eb18cf941
 DAUC vector [1]: ik = 79f21ed53bcb47787de57d136ff803a5
@@ -145,7 +145,7 @@
 DAUC vector [1]: sres = 882b1d59
 DAUC vector [1]: auth_types = 0x3
 DAUC vector [2]: rand = ab9432c2190049b12da4352bb02bac61
-DAUC vector [2]: sqn = 26
+DAUC vector [2]: sqn = 25
 DAUC vector [2]: autn = 24b018d46c3b00009c7e1b47f3a19b2b
 DAUC vector [2]: ck = d86c3191a36fc0602e48202ef2080964
 DAUC vector [2]: ik = 648dab72016181406243420649e63dc9
@@ -155,18 +155,18 @@
 DAUC vector [2]: sres = cd6f0df5
 DAUC vector [2]: auth_types = 0x3
 rc == 3
-aud3g.u.umts.sqn == 27
+aud3g.u.umts.sqn == 26
 [0]: vector matches expectations
 [1]: vector matches expectations
 [2]: vector matches expectations
-Now reach sqn = 24 with AUTS and expect the same
+Now reach sqn = 23 with AUTS and expect the same
 DAUC Computing 3 auth vectors: 3G only (2G derived from 3G keys), with AUTS resync
 DAUC 3G: k = eb215756028d60e3275e613320aec880
 DAUC 3G: opc = fb2a3d1b360f599abab99db8669f8308
 DAUC vector [0]: rand = 897210a0f7de278f0b8213098e098a3f
 DAUC vector [0]: resync: auts = 979498b1f72d3e28c59fa2e72f9c
 DAUC vector [0]: resync: rand_auts = 39fa2f4e3d523d8619a73b4f65c3e14d
-DAUC vector [0]: resync: sqn = 24
+DAUC vector [0]: resync: sqn = 23
 DAUC vector [0]: autn = c6b9790dad4b00000cf322869ea6a481
 DAUC vector [0]: ck = e9922bd036718ed9e40bd1d02c3b81a5
 DAUC vector [0]: ik = f19c20ca863137f8892326d959ec5e01
@@ -176,7 +176,7 @@
 DAUC vector [0]: sres = 0ad888ef
 DAUC vector [0]: auth_types = 0x3
 DAUC vector [1]: rand = 9a8321b108ef38a01c93241a9f1a9b50
-DAUC vector [1]: sqn = 25
+DAUC vector [1]: sqn = 24
 DAUC vector [1]: autn = 79a5113eb0910000be6020540503ffc5
 DAUC vector [1]: ck = 3686f05df057d1899c66ae4eb18cf941
 DAUC vector [1]: ik = 79f21ed53bcb47787de57d136ff803a5
@@ -186,7 +186,7 @@
 DAUC vector [1]: sres = 882b1d59
 DAUC vector [1]: auth_types = 0x3
 DAUC vector [2]: rand = ab9432c2190049b12da4352bb02bac61
-DAUC vector [2]: sqn = 26
+DAUC vector [2]: sqn = 25
 DAUC vector [2]: autn = 24b018d46c3b00009c7e1b47f3a19b2b
 DAUC vector [2]: ck = d86c3191a36fc0602e48202ef2080964
 DAUC vector [2]: ik = 648dab72016181406243420649e63dc9
diff --git a/tests/auc/auc_ts_55_205_test_sets.err b/tests/auc/auc_ts_55_205_test_sets.err
index 9a9aaf5..59ba22d 100644
--- a/tests/auc/auc_ts_55_205_test_sets.err
+++ b/tests/auc/auc_ts_55_205_test_sets.err
@@ -1,11 +1,11 @@
 
 ===== test_set_1
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 465b5ce8b199b49faa5f0a2ee238a6bc
 DAUC 3G: opc = cd63cb71954a9f4e48a5994e37a02baf
 DAUC vector [0]: rand = 23553cbe9637a89d218ae64dae47bf35
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = aa689c64835000002bb2bf2f1faba139
 DAUC vector [0]: ck = b40ba9a3c58b2a05bbf0d987b21bf8cb
 DAUC vector [0]: ik = f769bcd751044604127672711c6d3441
@@ -15,18 +15,18 @@
 DAUC vector [0]: sres = 46f8416a
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_1: SUCCESS
 
 
 ===== test_set_2
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = fec86ba6eb707ed08905757b1bb44b8f
 DAUC 3G: opc = 1006020f0a478bf6b699f15c062e42b3
 DAUC vector [0]: rand = 9f7c8d021accf4db213ccff0c7f71a6a
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 33484dc2134b000091ec125f4840ed64
 DAUC vector [0]: ck = 5dbdbb2954e8f3cde665b046179a5098
 DAUC vector [0]: ik = 59a92d3b476a0443487055cf88b2307b
@@ -36,18 +36,18 @@
 DAUC vector [0]: sres = 8c308a5e
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_2: SUCCESS
 
 
 ===== test_set_3
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 9e5944aea94b81165c82fbf9f32db751
 DAUC 3G: opc = a64a507ae1a2a98bb88eb4210135dc87
 DAUC vector [0]: rand = ce83dbc54ac0274a157c17f80d017bd6
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = f0b9c08ad00e00005da4ccbbdfa29310
 DAUC vector [0]: ck = e203edb3971574f5a94b0d61b816345d
 DAUC vector [0]: ik = 0c4524adeac041c4dd830d20854fc46b
@@ -57,18 +57,18 @@
 DAUC vector [0]: sres = cfbce3fe
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_3: SUCCESS
 
 
 ===== test_set_4
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 4ab1deb05ca6ceb051fc98e77d026a84
 DAUC 3G: opc = dcf07cbd51855290b92a07a9891e523e
 DAUC vector [0]: rand = 74b0cd6031a1c8339b2b6ce2b8c4a186
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 31e11a60913800006a7003718d5d82e5
 DAUC vector [0]: ck = 7657766b373d1c2138f307e3de9242f9
 DAUC vector [0]: ik = 1c42e960d89b8fa99f2744e0708ccb53
@@ -78,18 +78,18 @@
 DAUC vector [0]: sres = 9655e265
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_4: SUCCESS
 
 
 ===== test_set_5
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 6c38a116ac280c454f59332ee35c8c4f
 DAUC 3G: opc = 3803ef5363b947c6aaa225e58fae3934
 DAUC vector [0]: rand = ee6466bc96202c5a557abbeff8babf63
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 45b0f69ab04c000053f2a822f2b3e824
 DAUC vector [0]: ck = 3f8c7587fe8e4b233af676aede30ba3b
 DAUC vector [0]: ik = a7466cc1e6b2a1337d49d3b66e95d7b4
@@ -99,18 +99,18 @@
 DAUC vector [0]: sres = 13688f17
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_5: SUCCESS
 
 
 ===== test_set_6
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 2d609d4db0ac5bf0d2c0de267014de0d
 DAUC 3G: opc = c35a0ab0bcbfc9252caff15f24efbde0
 DAUC vector [0]: rand = 194aa756013896b74b4a2a3b0af4539e
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 7e6455f34cd300004a2a9f2f3a529b8c
 DAUC vector [0]: ck = 4cd0846020f8fa0731dd47cbdc6be411
 DAUC vector [0]: ik = 88ab80a415f15c73711254a1d388f696
@@ -120,18 +120,18 @@
 DAUC vector [0]: sres = 553d00b3
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_6: SUCCESS
 
 
 ===== test_set_7
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = a530a7fe428fad1082c45eddfce13884
 DAUC 3G: opc = 27953e49bc8af6dcc6e730eb80286be3
 DAUC vector [0]: rand = 3a4c2b3245c50eb5c71d08639395764d
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 88196c47984f00000a50c5f4056ccb68
 DAUC vector [0]: ck = 10f05bab75a99a5fbb98a9c287679c3b
 DAUC vector [0]: ik = f9ec0865eb32f22369cade40c59c3a44
@@ -141,18 +141,18 @@
 DAUC vector [0]: sres = 59f1a44a
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_7: SUCCESS
 
 
 ===== test_set_8
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = d9151cf04896e25830bf2e08267b8360
 DAUC 3G: opc = c4c93effe8a08138c203d4c27ce4e3d9
 DAUC vector [0]: rand = f761e5e93d603feb730e27556cb8a2ca
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 82a0f5287a5100006d6c0ff132426479
 DAUC vector [0]: ck = 71236b7129f9b22ab77ea7a54c96da22
 DAUC vector [0]: ik = 90527ebaa5588968db41727325a04d9e
@@ -162,18 +162,18 @@
 DAUC vector [0]: sres = 50588861
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_8: SUCCESS
 
 
 ===== test_set_9
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = a0e2971b6822e8d354a18cc235624ecb
 DAUC 3G: opc = 82a26f22bba9e9488f949a10d98e9cc4
 DAUC vector [0]: rand = 08eff828b13fdb562722c65c7f30a9b2
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = a2f858aa9e7d00001c14f5fcd445bc46
 DAUC vector [0]: ck = 08cef6d004ec61471a3c3cda048137fa
 DAUC vector [0]: ik = ed0318ca5deb9206272f6e8fa64ba411
@@ -183,18 +183,18 @@
 DAUC vector [0]: sres = cde6b027
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_9: SUCCESS
 
 
 ===== test_set_10
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 0da6f7ba86d5eac8a19cf563ac58642d
 DAUC 3G: opc = 0db1071f8767562ca43a0a64c41e8d08
 DAUC vector [0]: rand = 679ac4dbacd7d233ff9d6806f4149ce3
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 4c539a26e1da000071cc0b769fd1aa96
 DAUC vector [0]: ck = 69b1cae7c7429d975e245cacb05a517c
 DAUC vector [0]: ik = 74f24e8c26df58e1b38d7dcd4f1b7fbd
@@ -204,18 +204,18 @@
 DAUC vector [0]: sres = 02d13acd
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_10: SUCCESS
 
 
 ===== test_set_11
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 77b45843c88e58c10d202684515ed430
 DAUC 3G: opc = d483afae562409a326b5bb0b20c4d762
 DAUC vector [0]: rand = 4c47eb3076dc55fe5106cb2034b8cd78
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 30ff25cdadd60000e08a00f7ed54d6fe
 DAUC vector [0]: ck = 908c43f0569cb8f74bc971e706c36c5f
 DAUC vector [0]: ik = c251df0d888dd9329bcf46655b226e40
@@ -225,18 +225,18 @@
 DAUC vector [0]: sres = 44389d01
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_11: SUCCESS
 
 
 ===== test_set_12
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 729b17729270dd87ccdf1bfe29b4e9bb
 DAUC 3G: opc = 228c2f2f06ac3268a9e616ee16db4ba1
 DAUC vector [0]: rand = 311c4c929744d675b720f3b7e9b1cbd0
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 5380d158cfc30000f4e1436e9f67e4b2
 DAUC vector [0]: ck = 44c0f23c5493cfd241e48f197e1d1012
 DAUC vector [0]: ik = 0c9fb81613884c2535dd0eabf3b440d8
@@ -246,18 +246,18 @@
 DAUC vector [0]: sres = 03e0fd84
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_12: SUCCESS
 
 
 ===== test_set_13
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = d32dd23e89dc662354ca12eb79dd32fa
 DAUC 3G: opc = d22a4b4180a5325708a5ff70d9f67ec7
 DAUC vector [0]: rand = cf7d0ab1d94306950bf12018fbd46887
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 217af492728d00003bd338249751de80
 DAUC vector [0]: ck = 5af86b80edb70df5292cc1121cbad50c
 DAUC vector [0]: ik = 7f4d6ae7440e18789a8b75ad3f42f03a
@@ -267,18 +267,18 @@
 DAUC vector [0]: sres = be73b3dc
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_13: SUCCESS
 
 
 ===== test_set_14
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = af7c65e1927221de591187a2c5987a53
 DAUC 3G: opc = a4cf5c8155c08a7eff418e5443b98e55
 DAUC vector [0]: rand = 1f0f8578464fd59b64bed2d09436b57a
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 837fd7b744390000557a836fd534e542
 DAUC vector [0]: ck = 3f8c3f3ccf7625bf77fc94bcfd22fd26
 DAUC vector [0]: ik = abcbae8fd46115e9961a55d0da5f2078
@@ -288,18 +288,18 @@
 DAUC vector [0]: sres = 8fe019c7
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_14: SUCCESS
 
 
 ===== test_set_15
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 5bd7ecd3d3127a41d12539bed4e7cf71
 DAUC 3G: opc = 76089d3c0ff3efdc6e36721d4fceb747
 DAUC vector [0]: rand = 59b75f14251c75031d0bcbac1c2c04c7
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 5be11495527d0000298064f82a439924
 DAUC vector [0]: ck = d42b2d615e49a03ac275a5aef97af892
 DAUC vector [0]: ik = 0b3f8d024fe6bfafaa982b8f82e319c2
@@ -309,18 +309,18 @@
 DAUC vector [0]: sres = 27202b82
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_15: SUCCESS
 
 
 ===== test_set_16
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 6cd1c6ceb1e01e14f1b82316a90b7f3d
 DAUC 3G: opc = a219dc37f1dc7d66738b5843c799f206
 DAUC vector [0]: rand = f69b78f300a0568bce9f0cb93c4be4c9
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 1c408a858b1e0000e6e96310f83b5689
 DAUC vector [0]: ck = 6edaf99e5bd9f85d5f36d91c1272fb4b
 DAUC vector [0]: ik = d61c853c280dd9c46f297baec386de17
@@ -330,18 +330,18 @@
 DAUC vector [0]: sres = ddd7efe6
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_16: SUCCESS
 
 
 ===== test_set_17
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = b73a90cbcf3afb622dba83c58a8415df
 DAUC 3G: opc = df0c67868fa25f748b7044c6e7c245b8
 DAUC vector [0]: rand = b120f1c1a0102a2f507dd543de68281f
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = aefdaa5dddb90000c4741d698b7a7ed3
 DAUC vector [0]: ck = 66195dbed0313274c5ca7766615fa25e
 DAUC vector [0]: ik = 66bec707eb2afc476d7408a8f2927b36
@@ -351,18 +351,18 @@
 DAUC vector [0]: sres = 67e4ff3f
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_17: SUCCESS
 
 
 ===== test_set_18
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 5122250214c33e723a5dd523fc145fc0
 DAUC 3G: opc = 981d464c7c52eb6e5036234984ad0bcf
 DAUC vector [0]: rand = 81e92b6c0ee0e12ebceba8d92a99dfa5
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = ada15aeb7b980000a99729b59d5688b2
 DAUC vector [0]: ck = 5349fbe098649f948f5d2e973a81c00f
 DAUC vector [0]: ik = 9744871ad32bf9bbd1dd5ce54e3e2e5a
@@ -372,18 +372,18 @@
 DAUC vector [0]: sres = 8a3b8d17
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_18: SUCCESS
 
 
 ===== test_set_19
-aud3g.u.umts.sqn == 32
+aud3g.u.umts.sqn == 31
 DAUC Computing 1 auth vector: 3G only (2G derived from 3G keys)
 DAUC 3G: k = 90dca4eda45b53cf0f12d7c9c3bc6a89
 DAUC 3G: opc = cb9cccc4b9258e6dca4760379fb82581
 DAUC vector [0]: rand = 9fddc72092c6ad036b6e464789315b78
-DAUC vector [0]: sqn = 32
+DAUC vector [0]: sqn = 31
 DAUC vector [0]: autn = 83cfd54db9330000695685b2b9214472
 DAUC vector [0]: ck = b5f2da03883b69f96bf52e029ed9ac45
 DAUC vector [0]: ik = b4721368bc16ea67875c5598688bb0ef
@@ -393,7 +393,7 @@
 DAUC vector [0]: sres = df58522f
 DAUC vector [0]: auth_types = 0x3
 rc == 1
-aud3g.u.umts.sqn == 33
+aud3g.u.umts.sqn == 32
 vector matches expectations
 ===== test_set_19: SUCCESS
 
diff --git a/tests/auc/gen_ts_55_205_test_sets/func_template.c b/tests/auc/gen_ts_55_205_test_sets/func_template.c
index 83c5826..0865432 100644
--- a/tests/auc/gen_ts_55_205_test_sets/func_template.c
+++ b/tests/auc/gen_ts_55_205_test_sets/func_template.c
@@ -36,7 +36,7 @@
         aud3g = (struct osmo_sub_auth_data){{
                 .type = OSMO_AUTH_TYPE_UMTS,
                 .algo = OSMO_AUTH_ALG_MILENAGE,
-		.u.umts.sqn = 32,
+		.u.umts.sqn = 31,
         }};
 
         osmo_hexparse("{Ki}",
@@ -48,10 +48,10 @@
                       fake_rand, sizeof(fake_rand));
 
         vec = (struct osmo_auth_vector){{ {{0}} }};
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 31, "%"PRIu64);
         rc = auc_compute_vectors(&vec, 1, &aud2g, &aud3g, NULL, NULL);
         VERBOSE_ASSERT(rc, == 1, "%d");
-	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 33, "%"PRIu64);
+	VERBOSE_ASSERT(aud3g.u.umts.sqn, == 32, "%"PRIu64);
 
         VEC_IS(&vec,
                "  rand: {RAND}\n"