diff --git a/net_design.cc b/net_design.cc
index 6a9ebe386..84f4a7a34 100644
--- a/net_design.cc
+++ b/net_design.cc
@@ -409,7 +409,7 @@ void NetScope::evaluate_parameter_logic_(Design*des, param_ref_t cur)
 	   sure the type is set right. Note that if the parameter
 	   doesn't have an explicit type or range, then it will get
 	   the signedness from the expression itself. */
-      if ((*cur).second.signed_flag || range_flag) {
+      if (range_flag) {
 	    /* If we have a real value convert it to an integer. */
 	    if(NetECReal*tmp = dynamic_cast<NetECReal*>(expr)) {
 		  verinum nval(tmp->value().as_long64(), (unsigned)lv_width);
@@ -419,6 +419,8 @@ void NetScope::evaluate_parameter_logic_(Design*des, param_ref_t cur)
 	    }
 
             (*cur).second.val->cast_signed((*cur).second.signed_flag);
+      } else if ((*cur).second.signed_flag) {
+            (*cur).second.val->cast_signed(true);
       }
 
 	// If there are no value ranges to test the value against,