diff --git a/Grbl_Esp32/src/ControlPin.cpp b/Grbl_Esp32/src/ControlPin.cpp
index 671c43f3..56170cb2 100644
--- a/Grbl_Esp32/src/ControlPin.cpp
+++ b/Grbl_Esp32/src/ControlPin.cpp
@@ -10,21 +10,24 @@ void IRAM_ATTR ControlPin::handleISR() {
 }
 
 void ControlPin::init() {
-    if (_pin.defined()) {
-        _pin.report(_legend);
-        auto attr = Pin::Attr::Input | Pin::Attr::ISR;
-        if (_pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
-            attr = attr | Pin::Attr::PullUp;
-        }
-        _pin.setAttr(attr);
-        _pin.attachInterrupt<ControlPin, &ControlPin::handleISR>(this, CHANGE);
+    if (_pin.undefined() || _pin.name() == "NO_PIN") {
+        return;
     }
+    _pin.report(_legend);
+    auto attr = Pin::Attr::Input | Pin::Attr::ISR;
+    if (_pin.capabilities().has(Pins::PinCapabilities::PullUp)) {
+        attr = attr | Pin::Attr::PullUp;
+    }
+    _pin.setAttr(attr);
+    _pin.attachInterrupt<ControlPin, &ControlPin::handleISR>(this, CHANGE);
 }
 
 void ControlPin::report(char* status) {
-    if (!_pin.undefined()) {
-        addPinReport(status, _letter);
+    if (_pin.undefined() || _pin.name() == "NO_PIN") {
+        return;
     }
+
+    addPinReport(status, _letter);
 }
 
 ControlPin::~ControlPin() {
diff --git a/Grbl_Esp32/src/UserOutput.cpp b/Grbl_Esp32/src/UserOutput.cpp
index 8a8d6b4c..6e2e2f7c 100644
--- a/Grbl_Esp32/src/UserOutput.cpp
+++ b/Grbl_Esp32/src/UserOutput.cpp
@@ -23,10 +23,9 @@
 
 namespace UserOutput {
     DigitalOutput::DigitalOutput(uint8_t number, Pin& pin) : _number(number), _pin(pin) {
-        if (_pin.undefined()) {
+        if (_pin.undefined() || _pin.name() == "NO_PIN") {
             return;
         }
-
         init();
     }
 
@@ -51,7 +50,7 @@ namespace UserOutput {
     // ==================================================================
 
     AnalogOutput::AnalogOutput(uint8_t number, Pin& pin, float pwm_frequency) : _number(number), _pin(pin), _pwm_frequency(pwm_frequency) {
-        if (pin.undefined()) {
+        if (_pin.undefined() || _pin.name() == "NO_PIN") {
             return;
         }