diff --git a/test/test_streamlayerformat.py b/test/test_streamlayerformat.py
index 093bbaee4..6e65e2b34 100644
--- a/test/test_streamlayerformat.py
+++ b/test/test_streamlayerformat.py
@@ -34,11 +34,11 @@ class TestStreamLayerMerger(unittest.TestCase):
   def create_empty_layer(self):
     return ''
 
-  def squash_layers(self, layers):
+  def squash_layers(self, layers, path_prefix=None):
     def get_layers():
       return [StringIO(layer) for layer in layers]
 
-    merger = StreamLayerMerger(get_layers)
+    merger = StreamLayerMerger(get_layers, path_prefix=path_prefix)
     merged_data = ''.join(merger.get_generator())
     return merged_data
 
@@ -395,5 +395,57 @@ class TestStreamLayerMerger(unittest.TestCase):
     except TarLayerReadException as ex:
       self.assertEquals('Could not read layer', ex.message)
 
+  def test_single_layer_with_prefix(self):
+    tar_layer = self.create_layer(
+      foo = 'some_file',
+      bar = 'another_file',
+      meh = 'third_file')
+
+    squashed = self.squash_layers([tar_layer], path_prefix='foo/')
+
+    self.assertHasFile(squashed, 'foo/some_file', 'foo')
+    self.assertHasFile(squashed, 'foo/another_file', 'bar')
+    self.assertHasFile(squashed, 'foo/third_file', 'meh')
+
+  def test_multiple_layers_overwrite_with_prefix(self):
+    second_layer = self.create_layer(
+      foo = 'some_file',
+      bar = 'another_file',
+      meh = 'third_file')
+
+    first_layer = self.create_layer(
+      top = 'another_file')
+
+    squashed = self.squash_layers([first_layer, second_layer], path_prefix='foo/')
+
+    self.assertHasFile(squashed, 'foo/some_file', 'foo')
+    self.assertHasFile(squashed, 'foo/third_file', 'meh')
+    self.assertHasFile(squashed, 'foo/another_file', 'top')
+
+
+  def test_superlong_filename(self):
+    tar_layer = self.create_layer(
+      meh = 'this_is_the_filename_that_never_ends_it_goes_on_and_on_my_friend_some_people_started')
+
+    squashed = self.squash_layers([tar_layer],
+        path_prefix='foo/')
+
+    self.assertHasFile(squashed, 'foo/this_is_the_filename_that_never_ends_it_goes_on_and_on_my_friend_some_people_started', 'meh')
+
+
+  def test_superlong_prefix(self):
+    tar_layer = self.create_layer(
+      foo = 'some_file',
+      bar = 'another_file',
+      meh = 'third_file')
+
+    squashed = self.squash_layers([tar_layer],
+        path_prefix='foo/bar/baz/something/foo/bar/baz/anotherthing/whatever/this/is/a/really/long/filename/that/goes/here/')
+
+    self.assertHasFile(squashed, 'foo/bar/baz/something/foo/bar/baz/anotherthing/whatever/this/is/a/really/long/filename/that/goes/here/some_file', 'foo')
+    self.assertHasFile(squashed, 'foo/bar/baz/something/foo/bar/baz/anotherthing/whatever/this/is/a/really/long/filename/that/goes/here/another_file', 'bar')
+    self.assertHasFile(squashed, 'foo/bar/baz/something/foo/bar/baz/anotherthing/whatever/this/is/a/really/long/filename/that/goes/here/third_file', 'meh')
+
+
 if __name__ == '__main__':
   unittest.main()