diff --git a/src/revpi_middleware/ios1/interface_ios.py b/src/revpi_middleware/ios1/interface_ios.py
index 21a28ea..5b4e553 100644
--- a/src/revpi_middleware/ios1/interface_ios.py
+++ b/src/revpi_middleware/ios1/interface_ios.py
@@ -19,6 +19,7 @@ class InterfaceInput:
         <interface name="com.revolutionpi.ios1.Input">
             <property name="address" type="n" access="read"/>
             <property name="bmk" type="s" access="read"/>
+            <property name="bitaddress" type="n" access="readwrite"/>
             <property name="byteorder" type="s" access="readwrite"/>
             <property name="defaultvalue" type="v" access="read"/>
             <property name="length" type="q" access="read"/>
@@ -53,6 +54,10 @@ class InterfaceInput:
     def bmk(self) -> str:
         return self.io.bmk
 
+    @property
+    def bitaddress(self) -> int:
+        return self.io._bitaddress
+
     @property
     def byteorder(self) -> str:
         return self.io.byteorder
@@ -99,6 +104,7 @@ class InterfaceOutput(InterfaceInput):
         <interface name="com.revolutionpi.ios1.Output">
             <property name="address" type="n" access="read"/>
             <property name="bmk" type="s" access="read"/>
+            <property name="bitaddress" type="n" access="readwrite"/>
             <property name="byteorder" type="s" access="readwrite"/>
             <property name="defaultvalue" type="v" access="read"/>
             <property name="length" type="q" access="read"/>