diff --git a/rtdata/languages/default b/rtdata/languages/default
index e08ef4442..e61dbf1e2 100644
--- a/rtdata/languages/default
+++ b/rtdata/languages/default
@@ -1466,7 +1466,7 @@ TP_EXPOS_WHITEPOINT_LABEL;Raw White Points
 TP_FILMSIMULATION_LABEL;Film Simulation
 TP_FILMSIMULATION_STRENGTH;Strength
 TP_FILMSIMULATION_ZEROCLUTSFOUND;Set HaldCLUT directory in Preferences
-TP_FILMSIMULATION_SLOWPARSEDIR;RawTherapee is configured to look for Hald CLUT images, which are used for the Film Simulation tool, in a folder which is taking too long to load.\nGo to Preferences > Image Processing > Film Simulation\nto see which folder is being used. You should either point RawTherapee to a folder which contains only Hald CLUT images and nothing more, or to an empty folder if you don't want to use the Film Simulation tool.\n\nRead the Film Simulation article in RawPedia for more information.
+TP_FILMSIMULATION_SLOWPARSEDIR;RawTherapee is configured to look for Hald CLUT images, which are used for the Film Simulation tool, in a folder which is taking too long to load.\nGo to Preferences > Image Processing > Film Simulation\nto see which folder is being used. You should either point RawTherapee to a folder which contains only Hald CLUT images and nothing more, or to an empty folder if you don't want to use the Film Simulation tool.\n\nRead the Film Simulation article in RawPedia for more information.\n\nDo you want to cancel the scan now?
 TP_FLATFIELD_AUTOSELECT;Auto-selection
 TP_FLATFIELD_BLURRADIUS;Blur radius
 TP_FLATFIELD_BLURTYPE;Blur type
diff --git a/rtgui/filmsimulation.cc b/rtgui/filmsimulation.cc
index 6052fdc87..93abe18fb 100644
--- a/rtgui/filmsimulation.cc
+++ b/rtgui/filmsimulation.cc
@@ -12,23 +12,35 @@ using namespace rtengine::procparams;
 namespace
 {
 
-void notifySlowParseDir (const std::chrono::system_clock::time_point& startedAt)
+bool notifySlowParseDir (const std::chrono::system_clock::time_point& startedAt)
 {
-    static bool alreadyNotified = false;
+    static enum
+    {
+        Undecided,
+        Cancel,
+        Continue
+    }
+    decision = Undecided;
 
-    if (alreadyNotified) {
-        return;
+    if (decision == Cancel) {
+        return false;
+    } else if (decision == Continue) {
+        return true;
     }
 
     const auto now = std::chrono::system_clock::now ();
     if (now - startedAt < std::chrono::seconds (10)) {
-        return;
+        return true;
     }
 
-    Gtk::MessageDialog dialog (M ("TP_FILMSIMULATION_SLOWPARSEDIR"), false, Gtk::MESSAGE_WARNING, Gtk::BUTTONS_OK, true);
-    dialog.run ();
-
-    alreadyNotified = true;
+    Gtk::MessageDialog dialog (M ("TP_FILMSIMULATION_SLOWPARSEDIR"), false, Gtk::MESSAGE_WARNING, Gtk::BUTTONS_YES_NO, true);
+    if (dialog.run () == Gtk::RESPONSE_YES) {
+        decision = Cancel;
+        return false;
+    } else {
+        decision = Continue;
+        return true;
+    }
 }
 
 }
@@ -227,7 +239,10 @@ int ClutComboBox::parseDir (const Glib::ustring& path)
 
                 dirs.push_back (std::move (dir));
 
-                notifySlowParseDir (startedAt);
+                if (!notifySlowParseDir (startedAt)) {
+                    m_model->clear ();
+                    return 0;
+                }
             }
 
             currDirs.clear ();
@@ -278,7 +293,10 @@ int ClutComboBox::parseDir (const Glib::ustring& path)
 
             ++fileCount;
 
-            notifySlowParseDir (startedAt);
+            if (!notifySlowParseDir (startedAt)) {
+                m_model->clear ();
+                return 0;
+            }
         }
     }