diff --git a/src/MATLAB/+http/+io/LBinProvider.m b/src/MATLAB/+http/+io/LBinProvider.m
index e9f0cced149548771ff7e2459a8a0179c87a6f49..946093f833f7d27d8fd94fa056ad596e6bdebab4 100644
--- a/src/MATLAB/+http/+io/LBinProvider.m
+++ b/src/MATLAB/+http/+io/LBinProvider.m
@@ -38,7 +38,7 @@ classdef LBinProvider < matlab.net.http.io.MultipartFormProvider
             for pidx = 1:count_packs
                 cend = min(cstart+chan_pack-1, size(im8,4));
                 
-                pack_sz = [cend-cstart+1, size(im8,[1,2,3])];
+                pack_sz = [cend-cstart+1, size(im8,[2,1,3])];
                 clen = lbin_hdr_size + prod(pack_sz);
                 
                 % Set up lbin parts headers (needs content-type and content-disposition)