diff --git a/src/thermostat/max1968.rs b/src/thermostat/max1968.rs
index 7db78c6..0014a17 100644
--- a/src/thermostat/max1968.rs
+++ b/src/thermostat/max1968.rs
@@ -144,7 +144,7 @@ impl MAX1968 {
     }
 
     pub fn power_down(&mut self) {
-        let _ = self.shdn.set_high();
+        let _ = self.shdn.set_low();
     }
 
     pub fn power_up(&mut self) {