diff --git a/src/visualization.jl b/src/visualization.jl
index 7efa50e..3f4c132 100644
--- a/src/visualization.jl
+++ b/src/visualization.jl
@@ -57,6 +57,9 @@ function param_box!(grid, row, labeltxt, observable::Observable; col=1)
             @warn "Invalid input for $labeltxt: $s"
         end
     end
+    on(observable) do val
+        box.displayed_string[] = string(val)
+    end
 end
 
 function multi_step!(state, n_steps, heat_obs::Observable, params_obs::Observable; step_method=step_gray_scott!, dx=1)