diff --git a/demos/cast/build.gradle b/demos/cast/build.gradle
index 868e3c7b43..a3c13b382d 100644
--- a/demos/cast/build.gradle
+++ b/demos/cast/build.gradle
@@ -38,6 +38,7 @@ android {
                 "proguard-rules.txt",
                 getDefaultProguardFile('proguard-android.txt')
             ]
+            signingConfig signingConfigs.debug
         }
         debug {
             jniDebuggable = true
diff --git a/demos/gl/build.gradle b/demos/gl/build.gradle
index e065f9b8f2..a2ffa7f41f 100644
--- a/demos/gl/build.gradle
+++ b/demos/gl/build.gradle
@@ -34,6 +34,7 @@ android {
             shrinkResources true
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt')
+            signingConfig signingConfigs.debug
         }
     }
 
diff --git a/demos/main/build.gradle b/demos/main/build.gradle
index c5554993dc..d9ec74e2c2 100644
--- a/demos/main/build.gradle
+++ b/demos/main/build.gradle
@@ -38,6 +38,7 @@ android {
                 "proguard-rules.txt",
                 getDefaultProguardFile('proguard-android.txt')
             ]
+            signingConfig signingConfigs.debug
         }
         debug {
             jniDebuggable = true
diff --git a/demos/surface/build.gradle b/demos/surface/build.gradle
index bff05901b5..38de169ae5 100644
--- a/demos/surface/build.gradle
+++ b/demos/surface/build.gradle
@@ -34,6 +34,7 @@ android {
             shrinkResources true
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt')
+            signingConfig signingConfigs.debug
         }
     }