diff --git a/docs/advanced.rst b/docs/advanced.rst
index 198a3d2..ed5aa08 100644
--- a/docs/advanced.rst
+++ b/docs/advanced.rst
@@ -97,8 +97,12 @@ Create your own method with the following signature
 
     def my_matcher(r1, r2):
 
-Your method receives the two requests and must return ``True`` if they
-match, ``False`` if they don't.
+Your method receives the two requests and can return :
+
+- Use an ``assert`` statement in the matcher, then we have ``None`` if they match, raise an `AssertionError`` if they don't.
+- A boolean, ``True`` if they match, ``False`` if they don't.
+
+Note : You should use an ``assert`` statement in order to have feedback when a matcher is failing.
 
 Finally, register your method with VCR to use your new request matcher.
 
@@ -107,7 +111,7 @@ Finally, register your method with VCR to use your new request matcher.
     import vcr
 
     def jurassic_matcher(r1, r2):
-        return r1.uri == r2.uri and 'JURASSIC PARK' in r1.body
+        assert r1.uri == r2.uri and 'JURASSIC PARK' in r1.body
 
     my_vcr = vcr.VCR()
     my_vcr.register_matcher('jurassic', jurassic_matcher)