diff --git a/expr_synth.cc b/expr_synth.cc
index c4d0c39c9..176f35c29 100644
--- a/expr_synth.cc
+++ b/expr_synth.cc
@@ -737,8 +737,16 @@ NetNet* NetEConcat::synthesize(Design*des, NetScope*scope, NetExpr*root)
 		  tmp[idx] = parms_[idx]->synthesize(des, scope, root);
 		  if (tmp[idx] == 0) flag = false;
 		    /* Set the data type to the first one found. */
-		  if (data_type == IVL_VT_NO_TYPE) {
-			 data_type = tmp[idx]->data_type();
+		  switch (data_type) {
+		      case IVL_VT_NO_TYPE:
+			data_type = tmp[idx]->data_type();
+			break;
+		      case IVL_VT_BOOL:
+			if (tmp[idx]->data_type()==IVL_VT_LOGIC)
+			      data_type = IVL_VT_LOGIC;
+			break;
+		      default:
+			break;
 		  }
 	    }
       }
diff --git a/netlist.cc b/netlist.cc
index 5727b6a81..0751f86f8 100644
--- a/netlist.cc
+++ b/netlist.cc
@@ -2359,11 +2359,13 @@ ivl_variable_type_t NetETernary::expr_type() const
       ivl_assert(*this, false_val_);
       ivl_variable_type_t tru = true_val_->expr_type();
       ivl_variable_type_t fal = false_val_->expr_type();
+      ivl_variable_type_t sel = cond_->expr_type();
       if (tru == IVL_VT_LOGIC && fal == IVL_VT_BOOL)
 	    return IVL_VT_LOGIC;
       if (tru == IVL_VT_BOOL && fal == IVL_VT_LOGIC)
 	    return IVL_VT_LOGIC;
-
+      if (sel == IVL_VT_LOGIC && (tru == IVL_VT_LOGIC || tru == IVL_VT_BOOL) && (fal == IVL_VT_LOGIC || fal == IVL_VT_BOOL))
+	    return IVL_VT_LOGIC;
       if (tru == IVL_VT_REAL && (fal == IVL_VT_LOGIC || fal == IVL_VT_BOOL))
 	    return IVL_VT_REAL;
       if (fal == IVL_VT_REAL && (tru == IVL_VT_LOGIC || tru == IVL_VT_BOOL))
diff --git a/vvp/logic.cc b/vvp/logic.cc
index a47ffcbeb..3e4a11a8d 100644
--- a/vvp/logic.cc
+++ b/vvp/logic.cc
@@ -24,6 +24,7 @@
 # include  "schedule.h"
 # include  "delay.h"
 # include  "statistics.h"
+# include  <iostream>
 # include  <cstring>
 # include  <cassert>
 # include  <cstdlib>