diff --git a/app/tools/gimplevelstool.c b/app/tools/gimplevelstool.c
index 3fc5af4396..785f755a66 100644
--- a/app/tools/gimplevelstool.c
+++ b/app/tools/gimplevelstool.c
@@ -32,12 +32,16 @@
 #include "operations/gimplevelsconfig.h"
 #include "operations/gimpoperationlevels.h"
 
+#include "core/gimp-gui.h"
 #include "core/gimpasync.h"
+#include "core/gimpcancelable.h"
 #include "core/gimpdrawable.h"
 #include "core/gimpdrawable-histogram.h"
 #include "core/gimperror.h"
 #include "core/gimphistogram.h"
 #include "core/gimpimage.h"
+#include "core/gimptoolinfo.h"
+#include "core/gimptriviallycancelablewaitable.h"
 #include "core/gimpwaitable.h"
 
 #include "widgets/gimpcolorbar.h"
@@ -1001,12 +1005,22 @@ levels_stretch_callback (GtkWidget      *widget,
 {
   GimpTool       *tool        = GIMP_TOOL (levels_tool);
   GimpFilterTool *filter_tool = GIMP_FILTER_TOOL (levels_tool);
+  GimpWaitable   *waitable;
 
-  gimp_waitable_wait (GIMP_WAITABLE (levels_tool->histogram_async));
+  waitable = gimp_trivially_cancelable_waitable_new (
+    GIMP_WAITABLE (levels_tool->histogram_async));
 
-  gimp_levels_config_stretch (GIMP_LEVELS_CONFIG (filter_tool->config),
-                              levels_tool->histogram,
-                              gimp_drawable_is_rgb (tool->drawable));
+  gimp_wait (tool->tool_info->gimp, waitable, _("Calculating histogram..."));
+
+  g_object_unref (waitable);
+
+  if (gimp_async_is_synced   (levels_tool->histogram_async) &&
+      gimp_async_is_finished (levels_tool->histogram_async))
+    {
+      gimp_levels_config_stretch (GIMP_LEVELS_CONFIG (filter_tool->config),
+                                  levels_tool->histogram,
+                                  gimp_drawable_is_rgb (tool->drawable));
+    }
 }
 
 static void
diff --git a/app/tools/gimpthresholdtool.c b/app/tools/gimpthresholdtool.c
index 3daf28a174..62c34b8ca6 100644
--- a/app/tools/gimpthresholdtool.c
+++ b/app/tools/gimpthresholdtool.c
@@ -25,11 +25,15 @@
 
 #include "tools-types.h"
 
+#include "core/gimp-gui.h"
 #include "core/gimpasync.h"
+#include "core/gimpcancelable.h"
 #include "core/gimpdrawable.h"
 #include "core/gimpdrawable-histogram.h"
 #include "core/gimphistogram.h"
 #include "core/gimpimage.h"
+#include "core/gimptoolinfo.h"
+#include "core/gimptriviallycancelablewaitable.h"
 #include "core/gimpwaitable.h"
 
 #include "widgets/gimphelp-ids.h"
@@ -399,22 +403,34 @@ static void
 gimp_threshold_tool_auto_clicked (GtkWidget         *button,
                                   GimpThresholdTool *t_tool)
 {
-  GimpHistogramChannel  channel;
-  gint                  n_bins;
-  gdouble               low;
+  GimpTool     *tool = GIMP_TOOL (t_tool);
+  GimpWaitable *waitable;
 
-  gimp_waitable_wait (GIMP_WAITABLE (t_tool->histogram_async));
+  waitable = gimp_trivially_cancelable_waitable_new (
+    GIMP_WAITABLE (t_tool->histogram_async));
 
-  g_object_get (GIMP_FILTER_TOOL (t_tool)->config,
-                "channel", &channel,
-                NULL);
+  gimp_wait (tool->tool_info->gimp, waitable, _("Calculating histogram..."));
 
-  n_bins = gimp_histogram_n_bins (t_tool->histogram);
+  g_object_unref (waitable);
 
-  low = gimp_histogram_get_threshold (t_tool->histogram,
-                                      channel,
-                                      0, n_bins - 1);
+  if (gimp_async_is_synced   (t_tool->histogram_async) &&
+      gimp_async_is_finished (t_tool->histogram_async))
+    {
+      GimpHistogramChannel channel;
+      gint                 n_bins;
+      gdouble              low;
 
-  gimp_histogram_view_set_range (t_tool->histogram_box->view,
-                                 low, n_bins - 1);
+      g_object_get (GIMP_FILTER_TOOL (t_tool)->config,
+                    "channel", &channel,
+                    NULL);
+
+      n_bins = gimp_histogram_n_bins (t_tool->histogram);
+
+      low = gimp_histogram_get_threshold (t_tool->histogram,
+                                          channel,
+                                          0, n_bins - 1);
+
+      gimp_histogram_view_set_range (t_tool->histogram_box->view,
+                                     low, n_bins - 1);
+    }
 }