diff --git a/doc/THANKS b/doc/THANKS
index 106f2ca60..86915b631 100644
--- a/doc/THANKS
+++ b/doc/THANKS
@@ -31,7 +31,7 @@ Daniele Bellucci <daniele.bellucci@gmail.com>
     2006
 
 Anthony Boynes <aboynes@gmail.com>
-    for reporting a bug
+    for reporting few bugs
 
 Velky Brat <velkybrat@gmail.com>
     for suggesting a minor enhancement to the bisection algorithm
diff --git a/lib/request/comparison.py b/lib/request/comparison.py
index 30b17df4f..27f5cf895 100644
--- a/lib/request/comparison.py
+++ b/lib/request/comparison.py
@@ -72,7 +72,10 @@ def comparison(page, getRatioValue=False, pageLength=None):
     else:
         seqMatcher.set_seq1(getFilteredPageContent(seqMatcher.a, True) if conf.textOnly else seqMatcher.a)
         seqMatcher.set_seq2(getFilteredPageContent(page, True) if conf.textOnly else page)
-        ratio = round(seqMatcher.quick_ratio(), 3)
+        if seqMatcher.a is None or seqMatcher.b is None:
+            ratio = None
+        else:
+            ratio = round(seqMatcher.quick_ratio(), 3)
 
     # If the url is stable and we did not set yet the match ratio and the
     # current injected value changes the url page content