diff --git a/PExpr.cc b/PExpr.cc
index 614ff34b8..7ee5f9298 100644
--- a/PExpr.cc
+++ b/PExpr.cc
@@ -152,7 +152,7 @@ bool PECallFunction::has_aa_term(Design*des, NetScope*scope) const
 }
 
 PEConcat::PEConcat(const svector<PExpr*>&p, PExpr*r)
-: parms_(p), repeat_(r)
+: parms_(p), tested_widths_(p.count()), repeat_(r)
 {
 }
 
diff --git a/PExpr.h b/PExpr.h
index 3d6be4ab0..e043da23a 100644
--- a/PExpr.h
+++ b/PExpr.h
@@ -21,6 +21,7 @@
 
 # include  <string>
 # include  <vector>
+# include  <valarray>
 # include  "netlist.h"
 # include  "verinum.h"
 # include  "LineInfo.h"
@@ -181,7 +182,10 @@ class PEConcat : public PExpr {
 				     bool bidirectional_flag) const;
     private:
       svector<PExpr*>parms_;
+      std::valarray<unsigned>tested_widths_;
+
       PExpr*repeat_;
+
 };
 
 /*
diff --git a/elab_expr.cc b/elab_expr.cc
index e4c998ff5..6c32fc4c9 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -1366,8 +1366,10 @@ unsigned PEConcat::test_width(Design*des, NetScope*scope,
       expr_type_ = IVL_VT_LOGIC;
 
       unsigned count_width = 0;
-      for (unsigned idx = 0 ; idx < parms_.count() ; idx += 1)
-	    count_width += parms_[idx]->test_width(des, scope, 0, 0, expr_type__, unsized_flag);
+      for (unsigned idx = 0 ; idx < parms_.count() ; idx += 1) {
+	    tested_widths_[idx] = parms_[idx]->test_width(des, scope, 0, 0, expr_type__, unsized_flag);
+	    count_width += tested_widths_[idx];
+      }
 
       if (repeat_) {
 	      // The repeat expression is self-determined and its own type.
@@ -1462,7 +1464,8 @@ NetExpr* PEConcat::elaborate_expr(Design*des, NetScope*scope,
 	    }
 
 	    assert(parms_[idx]);
-	    NetExpr*ex = elab_and_eval(des, scope, parms_[idx], 0, 0);
+	    NetExpr*ex = elab_and_eval(des, scope, parms_[idx],
+				       tested_widths_[idx], 0);
 	    if (ex == 0) continue;
 
 	    ex->set_line(*parms_[idx]);
@@ -2789,6 +2792,12 @@ NetExpr*PETernary::elaborate_expr(Design*des, NetScope*scope,
 			cerr << get_fileline() << ": debug: Short-circuit "
 			        "elaborate TRUE clause of ternary."
 			     << endl;
+		  if (use_wid <= 0) {
+			cerr << get_fileline() << ": internal error: "
+			     << "Unexpected use_wid=" << use_wid
+			     << " processing short-circuit TRUE clause"
+			     << " of expression: " << *this << endl;
+		  }
 		  ivl_assert(*this, use_wid > 0);
 		  NetExpr*tru = elab_and_eval(des, scope, tru_, use_wid);
 		  return pad_to_width(tru, use_wid);
@@ -2801,6 +2810,12 @@ NetExpr*PETernary::elaborate_expr(Design*des, NetScope*scope,
 			cerr << get_fileline() << ": debug: Short-circuit "
 			        "elaborate FALSE clause of ternary."
 			<< endl;
+		  if (use_wid <= 0) {
+			cerr << get_fileline() << ": internal error: "
+			     << "Unexpected use_wid=" << use_wid
+			     << " processing short-circuit FALSE clause"
+			     << " of expression: " << *this << endl;
+		  }
 		  ivl_assert(*this, use_wid > 0);
 		  NetExpr*fal = elab_and_eval(des, scope, fal_, use_wid);
 		  return pad_to_width(fal, use_wid);