diff --git a/elab_expr.cc b/elab_expr.cc
index 673afb19b..13d4d6459 100644
--- a/elab_expr.cc
+++ b/elab_expr.cc
@@ -1923,6 +1923,23 @@ NetExpr* PECallFunction::elaborate_base_(Design*des, NetScope*scope, NetScope*ds
 
       bool need_const = NEED_CONST & flags;
 
+	// If this is a constant expression, it is possible that we
+	// are being elaborated before the function definition. If
+	// that's the case, try to elaborate the function as a const
+	// function.
+      if (need_const && ! def->proc()) {
+	    if (debug_elaborate) {
+		  cerr << get_fileline() << ": PECallFunction::elaborate_base_: "
+		       << "Try to elaborate " << scope_path(dscope)
+		       << " as constant function." << endl;
+	    }
+	    dscope->set_elab_stage(2);
+	    dscope->need_const_func(true);
+	    const PFunction*pfunc = dscope->func_pform();
+	    ivl_assert(*this, pfunc);
+	    pfunc->elaborate(des, dscope);
+      }
+
       unsigned parms_count = parms_.size();
       if ((parms_count == 1) && (parms_[0] == 0))
 	    parms_count = 0;
diff --git a/net_func_eval.cc b/net_func_eval.cc
index f5bef42c4..db2dd2260 100644
--- a/net_func_eval.cc
+++ b/net_func_eval.cc
@@ -87,11 +87,22 @@ NetExpr* NetFuncDef::evaluate_function(const LineInfo&loc, const std::vector<Net
 	// fills in the context_map with local variables held by the scope.
       scope_->evaluate_function_find_locals(loc, context_map);
 
+      if (debug_eval_tree && statement_==0) {
+	    cerr << loc.get_fileline() << ": NetFuncDef::evaluate_function: "
+		 << "Function " << scope_path(scope_)
+		 << " has no statement?" << endl;
+      }
+
 	// Perform the evaluation. Note that if there were errors
 	// when compiling the function definition, we may not have
 	// a valid statement.
       bool flag = statement_ && statement_->evaluate_function(loc, context_map);
 
+      if (debug_eval_tree && !flag) {
+	    cerr << loc.get_fileline() << ": NetFuncDef::evaluate_function: "
+		 << "Cannot evaluate " << scope_path(scope_) << "." << endl;
+      }
+
 	// Extract the result...
       ptr = context_map.find(scope_->basename());
       NetExpr*res = ptr->second.value;