diff --git a/easy_thumbnails/files.py b/easy_thumbnails/files.py
index 79652796..5d59ade0 100644
--- a/easy_thumbnails/files.py
+++ b/easy_thumbnails/files.py
@@ -76,7 +76,7 @@ def get_thumbnailer(obj, relative_name=None):
         remote_source=obj is not None)
 
 
-def generate_all_aliases(fieldfile, include_global):
+def generate_all_aliases(fieldfile, include_global, force=False):
     """
     Generate all of a file's aliases.
 
@@ -84,12 +84,14 @@ def generate_all_aliases(fieldfile, include_global):
     :param include_global: A boolean which determines whether to generate
         thumbnails for project-wide aliases in addition to field, model, and
         app specific aliases.
+    :param force: Force the generation behaviour by setting the generate param
+        to either True or False as required.
     """
     all_options = aliases.all(fieldfile, include_global=include_global)
     if all_options:
         thumbnailer = get_thumbnailer(fieldfile)
         for options in all_options.values():
-            thumbnailer.get_thumbnail(options)
+            thumbnailer.get_thumbnail(options, force=force)
 
 
 def database_get_image_dimensions(file, close=False, dimensions=None):
@@ -484,7 +486,7 @@ def get_existing_thumbnail(self, thumbnail_options, high_resolution=False):
                     thumbnail_file.set_image_dimensions(exists)
                 return thumbnail_file
 
-    def get_thumbnail(self, thumbnail_options, save=True, generate=None,
+    def get_thumbnail(self, thumbnail_options, save=True, generate=None, force=False,
                       silent_template_exception=False):
         """
         Return a ``ThumbnailFile`` containing a thumbnail.
@@ -498,6 +500,9 @@ def get_thumbnail(self, thumbnail_options, save=True, generate=None,
         Force the generation behaviour by setting the ``generate`` param to
         either ``True`` or ``False`` as required.
 
+        Force re-generation behaviour (even if thumbnail already exists) by setting
+        the force param to either True or False as required.
+
         The new thumbnail image is generated using the ``thumbnail_options``
         dictionary. If the ``save`` argument is ``True`` (default), the
         generated thumbnail will be saved too.
@@ -507,7 +512,7 @@ def get_thumbnail(self, thumbnail_options, save=True, generate=None,
             generate = self.generate
 
         thumbnail = self.get_existing_thumbnail(thumbnail_options)
-        if not thumbnail:
+        if force or not thumbnail:
             if generate:
                 thumbnail = self.generate_thumbnail(
                     thumbnail_options,