diff --git a/lightning.pb-c.c b/lightning.pb-c.c
index 188f77dc2..31523655b 100644
--- a/lightning.pb-c.c
+++ b/lightning.pb-c.c
@@ -1163,7 +1163,7 @@ const ProtobufCMessageDescriptor anchor__descriptor =
   (ProtobufCMessageInit) anchor__init,
   NULL,NULL,NULL    /* reserved[123] */
 };
-static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
+static const ProtobufCFieldDescriptor open_channel__field_descriptors[8] =
 {
   {
     "seed",
@@ -1249,6 +1249,18 @@ static const ProtobufCFieldDescriptor open_channel__field_descriptors[7] =
     0,             /* flags */
     0,NULL,NULL    /* reserved1,reserved2, etc */
   },
+  {
+    "tx_version",
+    8,
+    PROTOBUF_C_LABEL_REQUIRED,
+    PROTOBUF_C_TYPE_UINT32,
+    0,   /* quantifier_offset */
+    offsetof(OpenChannel, tx_version),
+    NULL,
+    NULL,
+    0,             /* flags */
+    0,NULL,NULL    /* reserved1,reserved2, etc */
+  },
 };
 static const unsigned open_channel__field_indices_by_name[] = {
   6,   /* field[6] = anchor */
@@ -1258,11 +1270,12 @@ static const unsigned open_channel__field_indices_by_name[] = {
   3,   /* field[3] = revocation_hash */
   4,   /* field[4] = script_to_me */
   0,   /* field[0] = seed */
+  7,   /* field[7] = tx_version */
 };
 static const ProtobufCIntRange open_channel__number_ranges[1 + 1] =
 {
   { 1, 0 },
-  { 0, 7 }
+  { 0, 8 }
 };
 const ProtobufCMessageDescriptor open_channel__descriptor =
 {
@@ -1272,7 +1285,7 @@ const ProtobufCMessageDescriptor open_channel__descriptor =
   "OpenChannel",
   "",
   sizeof(OpenChannel),
-  7,
+  8,
   open_channel__field_descriptors,
   open_channel__field_indices_by_name,
   1,  open_channel__number_ranges,
diff --git a/lightning.pb-c.h b/lightning.pb-c.h
index 79ea350fd..e23a06223 100644
--- a/lightning.pb-c.h
+++ b/lightning.pb-c.h
@@ -166,6 +166,10 @@ struct  _OpenChannel
    * The anchor transaction details.
    */
   Anchor *anchor;
+  /*
+   * Maximum transaction version we support.
+   */
+  uint32_t tx_version;
   OpenChannel__LocktimeCase locktime_case;
   union {
     uint32_t locktime_seconds;
@@ -174,7 +178,7 @@ struct  _OpenChannel
 };
 #define OPEN_CHANNEL__INIT \
  { PROTOBUF_C_MESSAGE_INIT (&open_channel__descriptor) \
-    , 0, NULL, {0,NULL}, 0, NULL, OPEN_CHANNEL__LOCKTIME__NOT_SET, {} }
+    , 0, NULL, {0,NULL}, 0, NULL, 0, OPEN_CHANNEL__LOCKTIME__NOT_SET, {} }
 
 
 /*
diff --git a/lightning.proto b/lightning.proto
index b83708f40..82347e401 100644
--- a/lightning.proto
+++ b/lightning.proto
@@ -65,6 +65,8 @@ message open_channel {
   required uint64 commitment_fee = 6;
   // The anchor transaction details.
   required anchor anchor = 7;
+  // Maximum transaction version we support.
+  required uint32 tx_version = 8;
 }
 
 // Supply signature for commitment tx
diff --git a/pkt.c b/pkt.c
index 084b850ca..a06a9a5f5 100644
--- a/pkt.c
+++ b/pkt.c
@@ -50,6 +50,7 @@ struct pkt *openchannel_pkt(const tal_t *ctx,
 	o.anchor = anchor;
 	o.locktime_case = OPEN_CHANNEL__LOCKTIME_LOCKTIME_SECONDS;
 	o.locktime_seconds = rel_locktime_seconds;
+	o.tx_version = 1;
 	
 	return to_pkt(ctx, PKT__PKT_OPEN, &o);
 }