diff --git a/app/actions/image-commands.c b/app/actions/image-commands.c
index 94141ffcdc..21143b1895 100644
--- a/app/actions/image-commands.c
+++ b/app/actions/image-commands.c
@@ -195,7 +195,7 @@ image_convert_base_type_cmd_callback (GtkAction *action,
       if (dialog)
         gtk_widget_destroy (dialog);
 
-      if (! gimp_image_convert_type (image, value, NULL, &error))
+      if (! gimp_image_convert_type (image, value, NULL, NULL, &error))
         {
           gimp_message_literal (image->gimp,
                                 G_OBJECT (widget), GIMP_MESSAGE_WARNING,
diff --git a/app/core/gimpimage-convert-type.c b/app/core/gimpimage-convert-type.c
index cced88f350..68d2fd877c 100644
--- a/app/core/gimpimage-convert-type.c
+++ b/app/core/gimpimage-convert-type.c
@@ -42,32 +42,38 @@
 gboolean
 gimp_image_convert_type (GimpImage          *image,
                          GimpImageBaseType   new_type,
+                         GimpColorProfile   *dest_profile,
                          GimpProgress       *progress,
                          GError            **error)
 {
   GimpImageBaseType  old_type;
+  const Babl        *new_layer_format;
   GList             *all_layers;
   GList             *list;
   const gchar       *undo_desc    = NULL;
   GimpProgress      *sub_progress = NULL;
-  GimpColorProfile  *dest_profile = NULL;
   gint               nth_layer;
   gint               n_layers;
 
   g_return_val_if_fail (GIMP_IS_IMAGE (image), FALSE);
   g_return_val_if_fail (new_type != gimp_image_get_base_type (image), FALSE);
   g_return_val_if_fail (new_type != GIMP_INDEXED, FALSE);
+  g_return_val_if_fail (dest_profile == NULL || GIMP_IS_COLOR_PROFILE (dest_profile),
+                        FALSE);
   g_return_val_if_fail (progress == NULL || GIMP_IS_PROGRESS (progress), FALSE);
   g_return_val_if_fail (error == NULL || *error == NULL, FALSE);
 
-  gimp_set_busy (image->gimp);
+  new_layer_format = gimp_babl_format (new_type,
+                                       gimp_image_get_precision (image),
+                                       TRUE);
 
-  all_layers = gimp_image_get_layer_list (image);
-
-  n_layers = g_list_length (all_layers);
-
-  if (progress)
-    sub_progress = gimp_sub_progress_new (progress);
+  if (dest_profile &&
+      ! gimp_image_validate_color_profile_by_format (new_layer_format,
+                                                     dest_profile,
+                                                     NULL, error))
+    {
+      return FALSE;
+    }
 
   switch (new_type)
     {
@@ -83,6 +89,15 @@ gimp_image_convert_type (GimpImage          *image,
       g_return_val_if_reached (FALSE);
     }
 
+  gimp_set_busy (image->gimp);
+
+  all_layers = gimp_image_get_layer_list (image);
+
+  n_layers = g_list_length (all_layers);
+
+  if (progress)
+    sub_progress = gimp_sub_progress_new (progress);
+
   g_object_freeze_notify (G_OBJECT (image));
 
   gimp_image_undo_group_start (image, GIMP_UNDO_GROUP_IMAGE_CONVERT,
@@ -96,13 +111,13 @@ gimp_image_convert_type (GimpImage          *image,
 
   g_object_set (image, "base-type", new_type, NULL);
 
-  /* when converting to/from GRAY, convert to the new type's builtin
-   * profile.
+  /*  When converting to/from GRAY, convert to the new type's builtin
+   *  profile if none was passed.
    */
   if (old_type == GIMP_GRAY ||
       new_type == GIMP_GRAY)
     {
-      if (gimp_image_get_color_profile (image))
+      if (! dest_profile && gimp_image_get_color_profile (image))
         dest_profile = gimp_image_get_builtin_color_profile (image);
     }
 
diff --git a/app/core/gimpimage-convert-type.h b/app/core/gimpimage-convert-type.h
index 06250fbcd7..dc3400133d 100644
--- a/app/core/gimpimage-convert-type.h
+++ b/app/core/gimpimage-convert-type.h
@@ -21,6 +21,7 @@
 
 gboolean   gimp_image_convert_type (GimpImage          *image,
                                     GimpImageBaseType   new_type,
+                                    GimpColorProfile   *dest_profile,
                                     GimpProgress       *progress,
                                     GError            **error);
 
diff --git a/app/pdb/image-convert-cmds.c b/app/pdb/image-convert-cmds.c
index 197bbd2ddb..adadb9e040 100644
--- a/app/pdb/image-convert-cmds.c
+++ b/app/pdb/image-convert-cmds.c
@@ -64,7 +64,7 @@ image_convert_rgb_invoker (GimpProcedure         *procedure,
     {
       if (gimp_pdb_image_is_not_base_type (image, GIMP_RGB, error))
         {
-          success = gimp_image_convert_type (image, GIMP_RGB, NULL, error);
+          success = gimp_image_convert_type (image, GIMP_RGB, NULL, NULL, error);
         }
       else
         {
@@ -93,7 +93,7 @@ image_convert_grayscale_invoker (GimpProcedure         *procedure,
     {
       if (gimp_pdb_image_is_not_base_type (image, GIMP_GRAY, error))
         {
-          success = gimp_image_convert_type (image, GIMP_GRAY, NULL, error);
+          success = gimp_image_convert_type (image, GIMP_GRAY, NULL, NULL, error);
         }
       else
         {
@@ -292,8 +292,8 @@ register_image_convert_procs (GimpPDB *pdb)
                                "gimp-image-convert-grayscale");
   gimp_procedure_set_static_strings (procedure,
                                      "gimp-image-convert-grayscale",
-                                     "Convert specified image to grayscale (256 intensity levels)",
-                                     "This procedure converts the specified image to grayscale with 8 bits per pixel (256 intensity levels). This process requires an image in RGB or Indexed color mode.",
+                                     "Convert specified image to grayscale",
+                                     "This procedure converts the specified image to grayscale. This process requires an image in RGB or Indexed color mode.",
                                      "Spencer Kimball & Peter Mattis",
                                      "Spencer Kimball & Peter Mattis",
                                      "1995-1996",
diff --git a/libgimp/gimpimageconvert_pdb.c b/libgimp/gimpimageconvert_pdb.c
index 1ac21a570e..dccd3cb3b3 100644
--- a/libgimp/gimpimageconvert_pdb.c
+++ b/libgimp/gimpimageconvert_pdb.c
@@ -70,11 +70,10 @@ gimp_image_convert_rgb (gint32 image_ID)
  * gimp_image_convert_grayscale:
  * @image_ID: The image.
  *
- * Convert specified image to grayscale (256 intensity levels)
+ * Convert specified image to grayscale
  *
- * This procedure converts the specified image to grayscale with 8 bits
- * per pixel (256 intensity levels). This process requires an image in
- * RGB or Indexed color mode.
+ * This procedure converts the specified image to grayscale. This
+ * process requires an image in RGB or Indexed color mode.
  *
  * Returns: TRUE on success.
  **/
diff --git a/tools/pdbgen/pdb/image_convert.pdb b/tools/pdbgen/pdb/image_convert.pdb
index 77fcb90127..7d37bec5ed 100644
--- a/tools/pdbgen/pdb/image_convert.pdb
+++ b/tools/pdbgen/pdb/image_convert.pdb
@@ -37,7 +37,7 @@ HELP
 {
   if (gimp_pdb_image_is_not_base_type (image, GIMP_RGB, error))
     {
-      success = gimp_image_convert_type (image, GIMP_RGB, NULL, error);
+      success = gimp_image_convert_type (image, GIMP_RGB, NULL, NULL, error);
     }
   else
     {
@@ -49,12 +49,11 @@ CODE
 }
 
 sub image_convert_grayscale {
-    $blurb = 'Convert specified image to grayscale (256 intensity levels)';
+    $blurb = 'Convert specified image to grayscale';
 
     $help = <<'HELP';
-This procedure converts the specified image to grayscale with 8 bits
-per pixel (256 intensity levels). This process requires an image in RGB
-or Indexed color mode.
+This procedure converts the specified image to grayscale. This process
+requires an image in RGB or Indexed color mode.
 HELP
 
     &std_pdb_misc;
@@ -69,7 +68,7 @@ HELP
 {
   if (gimp_pdb_image_is_not_base_type (image, GIMP_GRAY, error))
     {
-      success = gimp_image_convert_type (image, GIMP_GRAY, NULL, error);
+      success = gimp_image_convert_type (image, GIMP_GRAY, NULL, NULL, error);
     }
   else
     {