diff --git a/pipelined/src/uncore/gpio.sv b/pipelined/src/uncore/gpio.sv
index 8b81b0b9a..30ef0e31a 100644
--- a/pipelined/src/uncore/gpio.sv
+++ b/pipelined/src/uncore/gpio.sv
@@ -91,7 +91,7 @@ module gpio (
       high_ip <= #1 0;
       low_ie <= #1 0;
       low_ip <= #1 0;
-      out_xor <= 1'b 0;
+      out_xor <= #1 0;
     end else begin
       // writes
       if (memwrite)