diff --git a/matlab/TCV/gdat_tcv.m b/matlab/TCV/gdat_tcv.m
index 452883672f9d0cbbc635b3912a2dc888a791116e..d716210ccd3c8e529bfa4057f52d80f64dd9c6a0 100644
--- a/matlab/TCV/gdat_tcv.m
+++ b/matlab/TCV/gdat_tcv.m
@@ -1366,7 +1366,7 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
       gdat_data.(sources_avail{i}).data_fullpath=[];
       gdat_data.(sources_avail{i}).label=[];
     end
-    if ~isfield(gdat_data.gdat_params,'trialindx') || gdat_data.gdat_params.trialindx < 0
+    if ~isempty(gdat_data.gdat_params.trialindx) && gdat_data.gdat_params.trialindx < 0
       gdat_data.gdat_params.trialindx = [];
     end