diff --git a/packages/CLPBN/clpbn/bp/BpSolver.cpp b/packages/CLPBN/clpbn/bp/BpSolver.cpp
index 6fe7c4851..c5f812f97 100644
--- a/packages/CLPBN/clpbn/bp/BpSolver.cpp
+++ b/packages/CLPBN/clpbn/bp/BpSolver.cpp
@@ -278,10 +278,14 @@ BpSolver::calculateFactor2VariableMsg (SpLink* link)
   const SpLinkSet& links = ninf(src)->getLinks();
   // calculate the product of messages that were sent
   // to factor `src', except from var `dst'
-  unsigned msgSize = 1;
+  Params::size_type msgSize = 1;
   for (unsigned i = 0; i < links.size(); i++) {
     msgSize *= links[i]->getVariable()->range();
   }
+  if (msgSize > Util::maxUnsigned()) {
+    cout << "error: an overflow occurred when sending bp message" << endl;
+    abort();
+  }
   unsigned repetitions = 1;
   Params msgProduct (msgSize, LogAware::multIdenty());
   if (Globals::logDomain) {
diff --git a/packages/CLPBN/clpbn/bp/FoveSolver.cpp b/packages/CLPBN/clpbn/bp/FoveSolver.cpp
index a82774217..e844c5b78 100644
--- a/packages/CLPBN/clpbn/bp/FoveSolver.cpp
+++ b/packages/CLPBN/clpbn/bp/FoveSolver.cpp
@@ -84,7 +84,7 @@ SumOutOperator::getLogCost (void)
     ++ pfIter;
   }
   if (nrProdFactors == 1) {
-    return std::log (1.0); // best possible case
+    return std::log (0.0); // best possible case
   }
   double cost = 1.0;
   for (unsigned i = 0; i < groupSet.size(); i++) {