diff --git a/w3af/core/controllers/misc/fuzzy_string_cmp.py b/w3af/core/controllers/misc/fuzzy_string_cmp.py
index 24d5a415b4..829b255f40 100644
--- a/w3af/core/controllers/misc/fuzzy_string_cmp.py
+++ b/w3af/core/controllers/misc/fuzzy_string_cmp.py
@@ -116,7 +116,7 @@ def relative_distance(a_str, b_str):
         #
         return difflib.SequenceMatcher(None, a_str, b_str).quick_ratio()
 
-    return len(set_a.intersection(set_b)) / max(len(set_a), len(set_b))
+    return 1.0 * len(set_a.intersection(set_b)) / max(len(set_a), len(set_b))
 
 
 def _generate_upper_bounds():
diff --git a/w3af/core/controllers/misc/tests/test_fuzzy_string_cmp.py b/w3af/core/controllers/misc/tests/test_fuzzy_string_cmp.py
index 400c325b74..24d68ca363 100644
--- a/w3af/core/controllers/misc/tests/test_fuzzy_string_cmp.py
+++ b/w3af/core/controllers/misc/tests/test_fuzzy_string_cmp.py
@@ -68,3 +68,17 @@ def test_all(self):
                   '    - Threshold: %s\n'\
             
             self.assertEqual(res1, res2, msg % (e, d, f))
+
+    def test_relative_distance(self):
+        acceptance_tests = []
+        acceptance_tests.append(('a', 'a', 1.0))
+        acceptance_tests.append(('ab ac ad', 'ab ae ad', 0.6))
+        acceptance_tests.append(('ab ac ae', 'ab af ad', 0.3))
+        acceptance_tests.append(('ab ac ad', 'aa ae af', 0.0))
+        acceptance_tests.append(('a', 'b', 0.0))
+        acceptance_tests.append(('aaaa', 'aaab', 0.75))
+        acceptance_tests.append(('a' * 25, 'a', 0.04))
+        for e, d, f in acceptance_tests:
+            res = relative_distance(e, d)
+            msg = "return value:%f, given value:%f" % (res, f)
+            self.assertTrue(res >= f, msg)
\ No newline at end of file