diff --git a/us_somo/develop/src/us_hydrodyn_mals_saxs_gui.cpp b/us_somo/develop/src/us_hydrodyn_mals_saxs_gui.cpp
index bfd7db41d..5f7a9ac78 100644
--- a/us_somo/develop/src/us_hydrodyn_mals_saxs_gui.cpp
+++ b/us_somo/develop/src/us_hydrodyn_mals_saxs_gui.cpp
@@ -5060,7 +5060,7 @@ void US_Hydrodyn_Mals_Saxs::update_enables()
    baseline_integral = ( ( US_Hydrodyn * ) us_hydrodyn )->gparams[ "mals_saxs_bl_integral" ] == "true";
 
    // pb_timeshift        ->setEnabled( files_selected_count > 0 && files_compatible && files_are_time );
-   pb_timeshift          ->setEnabled( files_selected_count - conc_selected_count > 0 && files_compatible && files_are_time && conc_files.size() );
+   pb_timeshift          ->setEnabled( (int64_t)files_selected_count - conc_selected_count > 0 && files_compatible && files_are_time && conc_files.size() );
    pb_timescale          ->setEnabled( files_selected_count && files_are_time && conc_selected_count == files_selected_count );
    pb_gauss_mode         ->setEnabled( files_selected_count == 1 && files_are_time );
    pb_gauss_start        ->setEnabled( files_selected_count == 1 && files_are_time );