diff --git a/src/drivers/linux_pwm_out/linux_pwm_out.cpp b/src/drivers/linux_pwm_out/linux_pwm_out.cpp
index 245c5fc0f2..7e8eb424d9 100644
--- a/src/drivers/linux_pwm_out/linux_pwm_out.cpp
+++ b/src/drivers/linux_pwm_out/linux_pwm_out.cpp
@@ -285,7 +285,7 @@ void task_main(int argc, char *argv[])
 			_controls[0].control[2] = 0.f;
 			int channel = rc_channels.function[rc_channels_s::RC_CHANNELS_FUNCTION_THROTTLE];
 
-			if (ret == 0 && channel >= 0 && channel < sizeof(rc_channels.channels) / sizeof(rc_channels.channels[0])) {
+			if (ret == 0 && channel >= 0 && channel < (int)(sizeof(rc_channels.channels) / sizeof(rc_channels.channels[0]))) {
 				_controls[0].control[3] = rc_channels.channels[channel];
 
 			} else {
@@ -347,7 +347,7 @@ void task_main(int argc, char *argv[])
 					pwm_value = _pwm_min;
 				}
 
-				for (int i = 0; i < _outputs.noutputs; ++i) {
+				for (uint32_t i = 0; i < _outputs.noutputs; ++i) {
 					pwm[i] = pwm_value;
 				}
 
diff --git a/src/drivers/linux_pwm_out/navio_sysfs.cpp b/src/drivers/linux_pwm_out/navio_sysfs.cpp
index 8ebcc9f111..4b5c992cc8 100644
--- a/src/drivers/linux_pwm_out/navio_sysfs.cpp
+++ b/src/drivers/linux_pwm_out/navio_sysfs.cpp
@@ -116,7 +116,7 @@ int NavioSysfsPWMOut::send_output_pwm(const uint16_t *pwm, int num_outputs)
 	int ret = 0;
 
 	//convert this to duty_cycle in ns
-	for (unsigned i = 0; i < num_outputs; ++i) {
+	for (int i = 0; i < num_outputs; ++i) {
 		int n = ::snprintf(data, sizeof(data), "%u", pwm[i] * 1000);
 		int write_ret = ::write(_pwm_fd[i], data, n);