diff --git a/src/DigitalOutputsClass.cpp b/src/DigitalOutputsClass.cpp
index 97eb7a4..cf492f4 100644
--- a/src/DigitalOutputsClass.cpp
+++ b/src/DigitalOutputsClass.cpp
@@ -77,7 +77,7 @@ void DigitalOutputsClass::write(uint8_t channel, PinStatus val) {
 
 void DigitalOutputsClass::writeAll(uint8_t val_mask) {
     for (uint8_t ch = 0; ch < 8; ch++) {
-        if (val_mask && (1 << ch)) {
+        if (val_mask & (1 << ch)) {
             write(ch, HIGH);
         } else {
             write(ch, LOW);
@@ -94,4 +94,4 @@ void DigitalOutputsClass::_setAutoRetryMode() {
 }
 
 DigitalOutputsClass MachineControl_DigitalOutputs;
-/**** END OF FILE ****/
\ No newline at end of file
+/**** END OF FILE ****/