diff --git a/contrib/ultrahdr.lua b/contrib/ultrahdr.lua
index ef7a61f..94df217 100644
--- a/contrib/ultrahdr.lua
+++ b/contrib/ultrahdr.lua
@@ -120,6 +120,7 @@ local COLORSPACE_TO_GUI_ACTION = {
     [DT_COLORSPACE_DISPLAY_P3] = 11
 }
 
+local UI_SLEEP_MS = 50 -- How many ms to sleep after UI action.
 
 local function set_log_level(level)
     local old_log_level = log.log_level()
@@ -221,9 +222,10 @@ local function set_profile(colorspace)
         local new = COLORSPACE_TO_GUI_ACTION[colorspace] or colorspace
         log.msg(log.debug, string.format("Changing export profile from %d to %d", old, new))
         dt.gui.action("lib/export/profile", 0, "selection", "next", new - old)
+        dt.control.sleep(UI_SLEEP_MS)
         return old
     else
-        -- Old method, timing-dependent
+        -- Old method
         return set_combobox("lib/export/profile", 0, "plugins/lighttable/export/icctype", colorspace)
     end
 end
@@ -238,12 +240,12 @@ local function set_combobox(path, instance, config_name, new_config_value)
     end
 
     dt.gui.action(path, 0, "selection", "first", 1.0)
-    dt.control.sleep(50)
+    dt.control.sleep(UI_SLEEP_MS)
     local limit, i = 30, 0 -- in case there is no matching config value in the first n entries of a combobox.
     while i < limit do
         i = i + 1
         dt.gui.action(path, 0, "selection", "next", 1.0)
-        dt.control.sleep(50)
+        dt.control.sleep(UI_SLEEP_MS)
         if dt.preferences.read("darktable", config_name, "integer") == new_config_value then
             log.msg(log.debug, string.format(_("Changed %s from %d to %d"), config_name, pref, new_config_value))
             return pref