diff --git a/examples/ConsoleShell/ConsoleShell.ino b/examples/ConsoleShell/ConsoleShell.ino
index e89469c..5e19d1d 100644
--- a/examples/ConsoleShell/ConsoleShell.ino
+++ b/examples/ConsoleShell/ConsoleShell.ino
@@ -140,7 +140,7 @@ void SetLedState()
 void SetBrightness() 
 {
   // clamp value intervalOn on 0 and PWMinterval
-  intervalOn  =  max(min(ledBrightness,PWMinterval),0);
+  intervalOn  =  max(min((unsigned long)ledBrightness,PWMinterval),0ul);
 }
 
 // Pulse Width Modulation to vary Led intensity
diff --git a/utility/HeaterSim.cpp b/utility/HeaterSim.cpp
index 8c546c4..237acdd 100644
--- a/utility/HeaterSim.cpp
+++ b/utility/HeaterSim.cpp
@@ -70,7 +70,7 @@ void HeaterSim::CalcTemperature()
 {
 	float rate                  = LN2/_halfTimeCooling;	 
 	unsigned long currentTime   = millis();
-	if (currentTime >= _lastTime) _deltams = max(currentTime - _lastTime,1);
+	if (currentTime >= _lastTime) _deltams = max(currentTime - _lastTime,1ul);
 	_deltaTime                  = _deltams/ 1000.0f;
 	float deltaTemp             = _boilerTemp - _ambientTemp;
 	float deltaTempAfterCooling = deltaTemp*exp(-rate*_deltaTime);