diff --git a/src/muz_qe/dl_context.cpp b/src/muz_qe/dl_context.cpp
index 0099b16f9..dfcaac791 100644
--- a/src/muz_qe/dl_context.cpp
+++ b/src/muz_qe/dl_context.cpp
@@ -814,6 +814,7 @@ namespace datalog {
 
     void context::transform_rules() {
         m_transf.reset();
+        m_transf.register_plugin(alloc(mk_coi_filter, *this));
         m_transf.register_plugin(alloc(mk_filter_rules, *this));        
         m_transf.register_plugin(alloc(mk_simple_joins, *this));
         if (unbound_compressor()) {