diff --git a/lib/mcp23008-17.js b/lib/mcp23008-17.js
index 0673d6e..2ed4a2f 100644
--- a/lib/mcp23008-17.js
+++ b/lib/mcp23008-17.js
@@ -13,9 +13,12 @@ class MCP23008 extends Device {
       this.ports = {}
       opts.portID = 'A'
       this.ports.A = new Port(opts)
+      console.log(this.ports.A)
         // if not specified there RPi is not managing the interrupt
         // pin number on RPi that is connected to and services the interrupt. 4/17/27/22 = 7/11/13/15
-      this.ports.A.interPin = opts.interPin.A ? opts.interPin.A : opts.interPin
+      if (opts.interPin) {
+        this.ports.A.interPin = opts.interPin.A ? opts.interPin.A : opts.interPin
+      }
     } // end constructor
 
   init() {
@@ -132,7 +135,9 @@ class MCP23017 extends MCP23008 {
       // add a second port
     opts.portID = 'B'
     this.ports.B = new Port(opts)
-    this.ports.B.interPin = opts.interPin.B ? opts.interPin.B : opts.interPin
+    if (opts.interPin) {
+      this.ports.B.interPin = opts.interPin.B ? opts.interPin.B : opts.interPin
+    }
   }
 
   pin(id, port) {