diff --git a/tools/signapk/Android.mk b/tools/signapk/Android.mk
index da1501b..c2cf572 100644
--- a/tools/signapk/Android.mk
+++ b/tools/signapk/Android.mk
@@ -19,7 +19,7 @@
 # ============================================================
 include $(CLEAR_VARS)
 LOCAL_MODULE := signapk
-LOCAL_SRC_FILES := SignApk.java
+LOCAL_SRC_FILES := $(call all-java-files-under, src)
 LOCAL_JAR_MANIFEST := SignApk.mf
 LOCAL_STATIC_JAVA_LIBRARIES := bouncycastle-host bouncycastle-bcpkix-host conscrypt-host
 LOCAL_REQUIRED_MODULES := libconscrypt_openjdk_jni
diff --git a/tools/signapk/SignApk.java b/tools/signapk/src/com/android/signapk/SignApk.java
similarity index 100%
rename from tools/signapk/SignApk.java
rename to tools/signapk/src/com/android/signapk/SignApk.java