diff --git a/setup/test.py b/setup/test.py
index ba364dd46d..71efa6fe70 100644
--- a/setup/test.py
+++ b/setup/test.py
@@ -62,6 +62,8 @@ def find_tests(which_tests=None):
     if ok('misc'):
         from calibre.ebooks.metadata.tag_mapper import find_tests
         a(find_tests())
+        from calibre.utils.shared_file import find_tests
+        a(find_tests())
 
     tests = unittest.TestSuite(ans)
     return tests
diff --git a/src/calibre/utils/shared_file.py b/src/calibre/utils/shared_file.py
index 217d409357..394c0cd86d 100644
--- a/src/calibre/utils/shared_file.py
+++ b/src/calibre/utils/shared_file.py
@@ -172,32 +172,34 @@ else:
     def raise_winerror(x):
         raise NotImplementedError(), None, sys.exc_info()[2]
 
-def test():
-    import repr as reprlib
-
-    def eq(x, y):
-        if x != y:
-            raise AssertionError('%s != %s' % (reprlib.repr(x), reprlib.repr(y)))
-
+def find_tests():
+    import unittest
     from calibre.ptempfile import TemporaryDirectory
-    with TemporaryDirectory() as tdir:
-        fname = os.path.join(tdir, 'test.txt')
-        with share_open(fname, 'wb') as f:
-            f.write(b'a' * 20 * 1024)
-            eq(fname, f.name)
-        f = share_open(fname, 'rb')
-        eq(f.read(1), b'a')
-        if iswindows:
-            os.rename(fname, fname+'.moved')
-            os.remove(fname+'.moved')
-        else:
-            os.remove(fname)
-        eq(f.read(1), b'a')
-        f2 = share_open(fname, 'w+b')
-        f2.write(b'b' * 10 * 1024)
-        f2.seek(0)
-        eq(f.read(10000), b'a'*10000)
-        eq(f2.read(100), b'b' * 100)
-        f3 = share_open(fname, 'rb')
-        eq(f3.read(100), b'b' * 100)
 
+    class SharedFileTest(unittest.TestCase):
+
+        def test_shared_file(self):
+            eq = self.assertEqual
+
+            with TemporaryDirectory() as tdir:
+                fname = os.path.join(tdir, 'test.txt')
+                with share_open(fname, 'wb') as f:
+                    f.write(b'a' * 20 * 1024)
+                    eq(fname, f.name)
+                f = share_open(fname, 'rb')
+                eq(f.read(1), b'a')
+                if iswindows:
+                    os.rename(fname, fname+'.moved')
+                    os.remove(fname+'.moved')
+                else:
+                    os.remove(fname)
+                eq(f.read(1), b'a')
+                f2 = share_open(fname, 'w+b')
+                f2.write(b'b' * 10 * 1024)
+                f2.seek(0)
+                eq(f.read(10000), b'a'*10000)
+                eq(f2.read(100), b'b' * 100)
+                f3 = share_open(fname, 'rb')
+                eq(f3.read(100), b'b' * 100)
+
+    return unittest.defaultTestLoader.loadTestsFromTestCase(SharedFileTest)