diff --git a/app/src/main/java/io/pslab/activity/CompassActivity.java b/app/src/main/java/io/pslab/activity/CompassActivity.java
index 2c86d7e45..dd285798b 100644
--- a/app/src/main/java/io/pslab/activity/CompassActivity.java
+++ b/app/src/main/java/io/pslab/activity/CompassActivity.java
@@ -152,9 +152,13 @@ public void onSensorChanged(SensorEvent event) {
         switch (direction) {
             case 0:
                 degree = Math.round(event.values[1]);
+                if (degree < 0)
+                    degree += 360;
                 break;
             case 1:
                 degree = Math.round(event.values[2]);
+                if (degree < 0)
+                    degree += 360;
                 break;
             case 2:
                 degree = Math.round(event.values[0]);