diff --git a/inst/shiny/stackPlot.R b/inst/shiny/stackPlot.R
index a13ce842c55eaa77544badfa2aec57f5929a75c5..279e67751cd05117e2809a27b30230197c2ce7f1 100644
--- a/inst/shiny/stackPlot.R
+++ b/inst/shiny/stackPlot.R
@@ -35,7 +35,7 @@ stackBarGroup_create <- reactive({
   }
   upperPlot <- plot_tox_stacks(chemicalSummary, 
                                chem_site, 
-                               category = ,
+                               category = category,
                                mean_logic = mean_logic,
                                include_legend = include_legend,
                                font_size = ifelse(catType == 2, 14, 17),