diff --git a/sensor/mcp9808/mcp9808.go b/sensor/mcp9808/mcp9808.go
index 66d9291..53b68a2 100644
--- a/sensor/mcp9808/mcp9808.go
+++ b/sensor/mcp9808/mcp9808.go
@@ -322,7 +322,11 @@ func convertWordToTempC(temp uint16) float64 {
 }
 
 func (d *MCP9808) setTemp(reg byte, newTemp float64) error {
-	return d.Bus.WriteWordToReg(address, reg, uint16(newTemp*16)&0x1fff)
+	rounder := 2.0
+	if newTemp < 0 {
+		rounder = 0.0
+	}
+	return d.Bus.WriteWordToReg(address, reg, uint16(newTemp*16+rounder)&0x1ffc)
 }
 
 // AmbientTemp reads the current sensor value along with the flags denoting what boundaries the