diff --git a/src/muz/transforms/dl_mk_quantifier_abstraction.cpp b/src/muz/transforms/dl_mk_quantifier_abstraction.cpp
index 5c0d442df..a22a67416 100644
--- a/src/muz/transforms/dl_mk_quantifier_abstraction.cpp
+++ b/src/muz/transforms/dl_mk_quantifier_abstraction.cpp
@@ -142,7 +142,8 @@ namespace datalog {
         m(ctx.get_manager()),
         m_ctx(ctx),
         a(m),
-        m_refs(m) {        
+        m_refs(m),
+        m_mc(NULL){        
     }
 
     mk_quantifier_abstraction::~mk_quantifier_abstraction() {