diff --git a/Tethering/proguard.flags b/Tethering/proguard.flags
index f62df7f..6735317 100644
--- a/Tethering/proguard.flags
+++ b/Tethering/proguard.flags
@@ -8,6 +8,10 @@
     native <methods>;
 }
 
+-keep class com.android.networkstack.tethering.util.TcUtils {
+    native <methods>;
+}
+
 -keepclassmembers public class * extends com.android.networkstack.tethering.util.Struct {
     *;
 }