diff --git a/audio-echo/app/build.gradle b/audio-echo/app/build.gradle
index 932b43346..982fe12df 100644
--- a/audio-echo/app/build.gradle
+++ b/audio-echo/app/build.gradle
@@ -13,13 +13,6 @@ android {
             }
         }
     }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'),
-                          'proguard-rules.pro'
-        }
-    }
     externalNativeBuild {
         cmake {
             path 'src/main/cpp/CMakeLists.txt'
diff --git a/audio-echo/app/proguard-rules.pro b/audio-echo/app/proguard-rules.pro
deleted file mode 100644
index 7dc6c7fbe..000000000
--- a/audio-echo/app/proguard-rules.pro
+++ /dev/null
@@ -1,17 +0,0 @@
-# Add project specific ProGuard rules here.
-# By default, the flags in this file are appended to flags specified
-# in /Users/gfan/dev/android-sdk/tools/proguard/proguard-android.txt
-# You can edit the include path and order by changing the proguardFiles
-# directive in build.gradle.
-#
-# For more details, see
-#   http://developer.android.com/guide/developing/tools/proguard.html
-
-# Add any project specific keep options here:
-
-# If your project uses WebView with JS, uncomment the following
-# and specify the fully qualified class name to the JavaScript interface
-# class:
-#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
-#   public *;
-#}