diff --git a/lighthub/inputs.cpp b/lighthub/inputs.cpp
index 88ca8f0..be006d9 100644
--- a/lighthub/inputs.cpp
+++ b/lighthub/inputs.cpp
@@ -1110,6 +1110,7 @@ uint8_t  readCache::digitalReadCached(uint8_t _pin)
   ///TBD
 }
 
+#ifdef MCP23017
 uint8_t  readCache::I2CReadBit(uint8_t _type, uint8_t _addr, uint8_t _pin)
 {
 if (addr!=_addr || type != _type)
@@ -1120,6 +1121,7 @@ if (addr!=_addr || type != _type)
 }
 return (cached_data >> _pin ) & 0x1;
 }
+#endif
 
 void readCache::invalidateInputCache()
 {
diff --git a/lighthub/inputs.h b/lighthub/inputs.h
index ddf7144..06d54e1 100644
--- a/lighthub/inputs.h
+++ b/lighthub/inputs.h
@@ -189,7 +189,9 @@ public:
   readCache();
   uint16_t analogReadCached (uint8_t pin);
   uint8_t  digitalReadCached(uint8_t pin);
+  #ifdef MCP23017
   uint8_t  I2CReadBit(uint8_t type, uint8_t addr, uint8_t pin);
+  #endif
   void invalidateInputCache();
 protected:
   uint8_t   addr;