diff --git a/src/muz/pdr/pdr_context.cpp b/src/muz/pdr/pdr_context.cpp
index 94dd5d0a0..d8b96297a 100644
--- a/src/muz/pdr/pdr_context.cpp
+++ b/src/muz/pdr/pdr_context.cpp
@@ -1221,6 +1221,7 @@ namespace pdr {
             remove_node(*m_root, false);
             dealloc(m_root);
             m_root = 0;
+            m_cache.reset();
         }
     }
 
diff --git a/src/tactic/sls/sls_tactic.cpp b/src/tactic/sls/sls_tactic.cpp
index ea5d60668..6783d9621 100644
--- a/src/tactic/sls/sls_tactic.cpp
+++ b/src/tactic/sls/sls_tactic.cpp
@@ -557,17 +557,12 @@ public:
     }
 
     virtual void cleanup() {        
-        imp * d = m_imp;
+        imp * d = alloc(imp, m, m_params, m_stats);
         #pragma omp critical (tactic_cancel)
         {
-            d = m_imp;
+            std::swap(d, m_imp);
         }
         dealloc(d);
-        d = alloc(imp, m, m_params, m_stats);
-        #pragma omp critical (tactic_cancel) 
-        {
-            m_imp = d;
-        }
     }
     
     virtual void collect_statistics(statistics & st) const {