diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index dd7dead..5e19247 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -1437,10 +1437,18 @@
 		gbprox_touch_tlli(peer, tlli_info, now);
 	}
 
-	if (parse_ctx->imsi && tlli_info && tlli_info->mi_data_len == 0)
+	if (parse_ctx->imsi && tlli_info && tlli_info->mi_data_len == 0) {
+		int enable_patching;
 		gbprox_update_tlli_info(tlli_info,
 					parse_ctx->imsi, parse_ctx->imsi_len);
 
+		/* Check, whether the IMSI matches */
+		enable_patching = gbprox_check_imsi(peer, parse_ctx->imsi,
+						    parse_ctx->imsi_len);
+		if (enable_patching >= 0)
+			tlli_info->enable_patching = enable_patching;
+	}
+
 	return tlli_info;
 }
 
diff --git a/openbsc/tests/gbproxy/gbproxy_test.ok b/openbsc/tests/gbproxy/gbproxy_test.ok
index 28d5016..a6ff674 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.ok
+++ b/openbsc/tests/gbproxy/gbproxy_test.ok
@@ -1797,17 +1797,17 @@
 CALLBACK, event 0, msg length 76, bvci 0x1002
 00 00 10 02 01 ef e2 b7 00 00 00 04 08 88 11 22 33 40 50 60 75 30 00 80 0e 00 35 01 c0 0d 0a 41 05 03 0c 00 00 1f 10 00 00 00 00 00 00 00 00 02 01 21 28 03 02 61 62 27 14 80 80 21 10 01 00 00 10 81 06 00 00 00 00 83 06 00 00 00 00 5a ff 02 
 
-NS UNITDATA MESSAGE to SGSN, BVCI 0x1002, msg length 76 (gprs_ns_sendmsg)
-MESSAGE to SGSN at 0x05060708:32000, msg length 80
-00 00 10 02 01 ef e2 b7 00 00 00 04 08 88 21 63 54 40 50 60 75 30 00 80 0e 00 35 01 c0 0d 0a 41 05 03 0c 00 00 1f 10 00 00 00 00 00 00 00 00 02 01 21 28 03 02 61 62 27 14 80 80 21 10 01 00 00 10 81 06 00 00 00 00 83 06 00 00 00 00 5a ff 02 
+NS UNITDATA MESSAGE to SGSN, BVCI 0x1002, msg length 71 (gprs_ns_sendmsg)
+MESSAGE to SGSN at 0x05060708:32000, msg length 75
+00 00 10 02 01 ef e2 b7 00 00 00 04 08 88 21 63 54 40 50 60 75 30 00 80 0e 00 30 01 c0 0d 0a 41 05 03 0c 00 00 1f 10 00 00 00 00 00 00 00 00 02 01 21 27 14 80 80 21 10 01 00 00 10 81 06 00 00 00 00 83 06 00 00 00 00 85 fa 60 
 
-result (ACT PDP CTX REQ (REMOVE APN)) = 80
+result (ACT PDP CTX REQ (REMOVE APN)) = 75
 
 Peers:
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
     RAID patched              (BSS ): 12
     RAID patched              (SGSN): 3
-    APN patched                     : 3
+    APN patched                     : 4
     Attach Request count            : 1
     TLLI cache size                 : 1
     TLLI-Cache: 1
@@ -1829,7 +1829,7 @@
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
     RAID patched              (BSS ): 13
     RAID patched              (SGSN): 3
-    APN patched                     : 3
+    APN patched                     : 4
     Attach Request count            : 1
     TLLI-Cache: 0
 --- Bad cases ---
@@ -1867,7 +1867,7 @@
   NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
     RAID patched              (BSS ): 14
     RAID patched              (SGSN): 3
-    APN patched                     : 3
+    APN patched                     : 4
     Attach Request count            : 1
     TLLI cache size                 : 1
     TLLI-Cache: 1