diff --git a/ultrasonic/src/main/java/org/moire/ultrasonic/fragment/MainFragment.java b/ultrasonic/src/main/java/org/moire/ultrasonic/fragment/MainFragment.kt
similarity index 100%
rename from ultrasonic/src/main/java/org/moire/ultrasonic/fragment/MainFragment.java
rename to ultrasonic/src/main/java/org/moire/ultrasonic/fragment/MainFragment.kt