diff --git a/compiler/options.py b/compiler/options.py
index 1899d085..b0b14dcc 100644
--- a/compiler/options.py
+++ b/compiler/options.py
@@ -48,6 +48,7 @@ class options(optparse.Values):
     # These are the configuration parameters
     rw_ports = 1
     r_ports = 0
+    w_ports = 0
     # These will get initialized by the the file
     supply_voltages = ""
     temperatures = ""