diff --git a/plugins/chanbackup.c b/plugins/chanbackup.c
index 1fb660a3f..11091edd9 100644
--- a/plugins/chanbackup.c
+++ b/plugins/chanbackup.c
@@ -665,7 +665,7 @@ static struct command_result *commit_peer_backup(struct command *cmd,
 						    "chanbackup/peers/%s",
 						    fmt_node_id(tmpctx,
 								&pb->peer)),
-					    pb->data,
+					    pb->data, tal_bytelen(pb->data),
 					    "create-or-replace",
 					    NULL, NULL, NULL);
 }
@@ -899,6 +899,7 @@ static struct command_result *handle_your_peer_storage(struct command *cmd,
 		return jsonrpc_set_datastore_binary(cmd,
 					     	    "chanbackup/latestscb",
 					     	    decoded_bkp,
+						    tal_bytelen(decoded_bkp),
 					     	    "create-or-replace",
 					     	    datastore_success,
 					     	    datastore_failed,
diff --git a/plugins/libplugin.c b/plugins/libplugin.c
index 896564f70..614b5d3db 100644
--- a/plugins/libplugin.c
+++ b/plugins/libplugin.c
@@ -912,7 +912,7 @@ void rpc_enable_batching(struct plugin *plugin)
 struct command_result *jsonrpc_set_datastore_(struct command *cmd,
 					      const char *path,
 					      const void *value,
-					      bool value_is_string,
+					      int len_or_str,
 					      const char *mode,
 					      struct command_result *(*cb)(struct command *command,
 									   const char *method,
@@ -936,10 +936,10 @@ struct command_result *jsonrpc_set_datastore_(struct command *cmd,
 	req = jsonrpc_request_start(cmd, "datastore", cb, errcb, arg);
 
 	json_add_keypath(req->js->jout, "key", path);
-	if (value_is_string)
+	if (len_or_str == -1)
 		json_add_string(req->js, "string", value);
 	else
-		json_add_hex_talarr(req->js, "hex", value);
+		json_add_hex(req->js, "hex", value, len_or_str);
 	json_add_string(req->js, "mode", mode);
 	return send_outreq(req);
 }
diff --git a/plugins/libplugin.h b/plugins/libplugin.h
index 54b4f883f..2cc781da8 100644
--- a/plugins/libplugin.h
+++ b/plugins/libplugin.h
@@ -272,7 +272,7 @@ struct json_stream *jsonrpc_stream_fail_data(struct command *cmd,
 struct command_result *jsonrpc_set_datastore_(struct command *cmd,
 					      const char *path,
 					      const void *value,
-					      bool value_is_string,
+					      int len_or_str,
 					      const char *mode,
 					      struct command_result *(*cb)(struct command *command,
 									   const char *method,
@@ -288,7 +288,7 @@ struct command_result *jsonrpc_set_datastore_(struct command *cmd,
 	NON_NULL_ARGS(1, 2, 3, 5);
 
 #define jsonrpc_set_datastore_string(cmd, path, str, mode, cb, errcb, arg) \
-	jsonrpc_set_datastore_((cmd), (path), (str), true, (mode),	\
+	jsonrpc_set_datastore_((cmd), (path), (str), -1, (mode),	\
 			       typesafe_cb_preargs(struct command_result *, void *, \
 						   (cb), (arg),		\
 						   struct command *command, \
@@ -303,8 +303,8 @@ struct command_result *jsonrpc_set_datastore_(struct command *cmd,
 						   const jsmntok_t *result), \
 			       (arg))
 
-#define jsonrpc_set_datastore_binary(cmd, path, tal_ptr, mode, cb, errcb, arg) \
-	jsonrpc_set_datastore_((cmd), (path), (tal_ptr), false, (mode), \
+#define jsonrpc_set_datastore_binary(cmd, path, ptr, len, mode, cb, errcb, arg) \
+	jsonrpc_set_datastore_((cmd), (path), (ptr), (len), (mode),	\
 			       typesafe_cb_preargs(struct command_result *, void *, \
 						   (cb), (arg),		\
 						   struct command *command, \