diff --git a/net_design.cc b/net_design.cc
index 4b4ba5692..6a9ebe386 100644
--- a/net_design.cc
+++ b/net_design.cc
@@ -405,11 +405,11 @@ void NetScope::evaluate_parameter_logic_(Design*des, param_ref_t cur)
       }
       (*cur).second.val = expr;
 
-	/* If the parameter has range information, then make
-	   sure the type is set right. Note that if the
-	   parameter doesn't have an explicit range, then it
-	   will get the signedness from the expression itself. */
-      if (range_flag) {
+	/* If the parameter has type or range information, then make
+	   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 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);
diff --git a/parse.y b/parse.y
index c783a21e4..3f4c78dbf 100644
--- a/parse.y
+++ b/parse.y
@@ -3312,6 +3312,16 @@ parameter_assign_decl
 	param_active_signed = false;
 	param_active_type = IVL_VT_LOGIC;
       }
+  | K_signed
+      { param_active_range = 0;
+	param_active_signed = true;
+	param_active_type = IVL_VT_LOGIC;
+      }
+    parameter_assign_list
+      { param_active_range = 0;
+	param_active_signed = false;
+	param_active_type = IVL_VT_LOGIC;
+      }
   | K_signed range
       { param_active_range = $2;
 	param_active_signed = true;
@@ -3427,6 +3437,16 @@ localparam_assign_decl
         param_active_signed = false;
 	param_active_type = IVL_VT_LOGIC;
       }
+  | K_signed
+      { param_active_range = 0;
+	param_active_signed = true;
+	param_active_type = IVL_VT_LOGIC;
+      }
+    localparam_assign_list
+      { param_active_range = 0;
+	param_active_signed = false;
+	param_active_type = IVL_VT_LOGIC;
+      }
   | K_signed range
       { param_active_range = $2;
 	param_active_signed = true;