diff --git a/ChangeLog b/ChangeLog
index 1c457e3ff..011f76bbe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2011-02-05  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
+
+	Fix call to scc_filter in the CGI script.
+
+	* wrap/python/ajax/spot.in: Do full scc_filter for TGBA (-R3f),
+	and keep some extra acceptance conditions (-R3) when
+	degeneralizing.  The converse was done.
+
 2011-02-04  Alexandre Duret-Lutz  <adl@lrde.epita.fr>
 
 	* wrap/python/cgi-bin/ltl2tgba.in: Fix python error occurring
diff --git a/wrap/python/ajax/spot.in b/wrap/python/ajax/spot.in
index 2dce02025..290411b2b 100755
--- a/wrap/python/ajax/spot.in
+++ b/wrap/python/ajax/spot.in
@@ -309,7 +309,7 @@ if prune_scc:
     # Do not suppress all useless acceptance conditions if
     # degeneralization is requested: keeping those that lead to
     # accepting states usually helps.
-    automaton = spot.scc_filter(automaton, degen)
+    automaton = spot.scc_filter(automaton, not degen)
 
 if wdba_minimize:
     minimized = spot.minimize_obligation_new(automaton, f)