diff --git a/src/app/IOManager.cpp b/src/app/IOManager.cpp
index 5226158..99a023a 100644
--- a/src/app/IOManager.cpp
+++ b/src/app/IOManager.cpp
@@ -11,6 +11,6 @@ PCF8574 &IOManager::getPcf()
 
 void IOManager::setISROnIOChange(void (*isrFunc)(), Pin pin)
 {
-  pinMode(pin, INPUT);
+  pinMode(pin, INPUT_PULLUP);
   attachInterrupt(digitalPinToInterrupt(pin), isrFunc, FALLING);
 }