diff --git a/eval_tree.cc b/eval_tree.cc
index 78d1e5b28..06b660df6 100644
--- a/eval_tree.cc
+++ b/eval_tree.cc
@@ -133,6 +133,8 @@ NetExpr* NetEBAdd::eval_tree(int prune_to_width)
 	    verinum lval = lc->value();
 	    verinum rval = rc->value();
 
+	    ivl_assert(*this, se->expr_width() == this->expr_width());
+
 	    verinum val;
 	    if (op_ == se->op_) {
 		    /* (a + lval) + rval  --> a + (rval+lval) */
@@ -144,6 +146,13 @@ NetExpr* NetEBAdd::eval_tree(int prune_to_width)
 		  val = rval - lval;
 	    }
 
+	    val = pad_to_width(val, expr_width());
+	    if (val.len() > expr_width()) {
+		  verinum tmp (val, expr_width());
+		  tmp.has_sign(val.has_sign());
+		  val = tmp;
+	    }
+
 	    NetEConst*tmp = new NetEConst(val);
 	    left_ = se->left_->dup_expr();
 	    delete se;
diff --git a/expr_synth.cc b/expr_synth.cc
index 2845877c9..9fe178fe1 100644
--- a/expr_synth.cc
+++ b/expr_synth.cc
@@ -99,8 +99,8 @@ NetNet* NetEBAdd::synthesize(Design*des, NetScope*scope)
 	    return 0;
       }
 
-      assert(expr_width() >= lsig->vector_width());
-      assert(expr_width() >= rsig->vector_width());
+      ivl_assert(*this, expr_width() >= lsig->vector_width());
+      ivl_assert(*this, expr_width() >= rsig->vector_width());
 
       unsigned width;
       if (expr_type() == IVL_VT_REAL) {
@@ -752,7 +752,7 @@ NetNet* NetEConst::synthesize(Design*des, NetScope*scope)
       perm_string path = scope->local_symbol();
       unsigned width=expr_width();
 
-      NetNet*osig = new NetNet(scope, path, NetNet::IMPLICIT, width-1,0);
+      NetNet*osig = new NetNet(scope, path, NetNet::IMPLICIT, width);
       osig->local_flag(true);
       osig->data_type(expr_type());
       osig->set_signed(has_sign());