diff --git a/src/sat/glucose2/Glucose2.cpp b/src/sat/glucose2/Glucose2.cpp
index f2ff3bcb5..ce553a6cb 100644
--- a/src/sat/glucose2/Glucose2.cpp
+++ b/src/sat/glucose2/Glucose2.cpp
@@ -187,6 +187,9 @@ Solver::Solver() :
   travId = 0;
   travId_prev = 0;
 
+  jlevel.push(-1);
+  jlevel.push(-1);
+
   // allocate space for clause interpretation 
   vec<Lit> tmp; tmp.growTo(3); 
   itpc = ca.alloc(tmp);
@@ -1911,6 +1914,9 @@ void Solver::reset()
     jlevel       .shrink_(jlevel.size());
     jnext        .shrink_(jnext.size());
 
+    jlevel.push(-1);
+    jlevel.push(-1);
+
     //var2FaninLits.shrink_(var2FaninLits.size());
     var2NodeData .shrink_(var2NodeData .size());
     var2Fanout0  .shrink_(var2Fanout0  .size());