diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index e8c3c38..12e587b 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -26,7 +26,7 @@ android {
             isMinifyEnabled = true
             isShrinkResources = true
             proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
-            isCrunchPngs = false
+            isCrunchPngs = true
         }
     }
     compileOptions {
diff --git a/app/src/main/java/it/edu/cassandroferminervi/flowschool/remote/dto/LoginResult.kt b/app/src/main/java/it/edu/cassandroferminervi/flowschool/remote/dto/LoginResult.kt
index 3e46a46..46c27ef 100644
--- a/app/src/main/java/it/edu/cassandroferminervi/flowschool/remote/dto/LoginResult.kt
+++ b/app/src/main/java/it/edu/cassandroferminervi/flowschool/remote/dto/LoginResult.kt
@@ -1,3 +1,6 @@
 package it.edu.cassandroferminervi.flowschool.remote.dto
 
+import androidx.annotation.Keep
+
+@Keep
 data class LoginResult(val token: String?, val error: String?)
diff --git a/build.gradle.kts b/build.gradle.kts
index 0db614e..a7d3dac 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -1,5 +1,5 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 plugins {
-    id("com.android.application") version "8.3.0" apply false
+    id("com.android.application") version "8.3.1" apply false
     id("org.jetbrains.kotlin.android") version "1.9.0" apply false
 }
\ No newline at end of file