diff --git a/src/api/api_datalog.cpp b/src/api/api_datalog.cpp
index 222d91081..394df7a17 100644
--- a/src/api/api_datalog.cpp
+++ b/src/api/api_datalog.cpp
@@ -130,7 +130,6 @@ namespace api {
         ast_manager& m = m_context.get_manager();
         
         datalog::context ctx(m, m_context.get_fparams());
-        // datalog::rule_manager& rm = ctx.get_rule_manager();
         for (unsigned i = 0; i < num_rules; ++i) {
             expr* rule = rules[i], *body, *head;
             while (true) {
diff --git a/src/muz_qe/pdr_context.cpp b/src/muz_qe/pdr_context.cpp
index c67cc6ad1..922a09448 100644
--- a/src/muz_qe/pdr_context.cpp
+++ b/src/muz_qe/pdr_context.cpp
@@ -1283,9 +1283,10 @@ namespace pdr {
                 for (it = rules.begin(); it != end; ++it) {  
                     datalog::rule& r = *(*it);
                     unsigned utsz = r.get_uninterpreted_tail_size();
+                    forms.push_back(r.get_head());
                     for (unsigned i = utsz; i < r.get_tail_size(); ++i) {
                         forms.push_back(r.get_tail(i));
-                    }                                          
+                    }         
                 }
                 m_is_dl = is_difference_logic(m, forms.size(), forms.c_ptr());
             }