diff --git a/app/build.gradle b/app/build.gradle
index ac98834..35461d1 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -19,8 +19,8 @@ android {
 
     buildTypes {
         release {
-            minifyEnabled false
-            shrinkResources false
+            minifyEnabled true
+            shrinkResources true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
diff --git a/app/proguard-rules.pro b/app/proguard-rules.pro
index f1b4245..534577a 100644
--- a/app/proguard-rules.pro
+++ b/app/proguard-rules.pro
@@ -15,7 +15,9 @@
 # Uncomment this to preserve the line number information for
 # debugging stack traces.
 #-keepattributes SourceFile,LineNumberTable
+-dontobfuscate
 
 # If you keep the line number information, uncomment this to
 # hide the original source file name.
 #-renamesourcefileattribute SourceFile
+-keep class org.mosad.seil0.projectlaogai.util.** { <fields>; }
\ No newline at end of file
diff --git a/app/src/main/java/org/mosad/seil0/projectlaogai/controller/cache/TimetableController.kt b/app/src/main/java/org/mosad/seil0/projectlaogai/controller/cache/TimetableController.kt
index 2e562f7..2863bfe 100644
--- a/app/src/main/java/org/mosad/seil0/projectlaogai/controller/cache/TimetableController.kt
+++ b/app/src/main/java/org/mosad/seil0/projectlaogai/controller/cache/TimetableController.kt
@@ -34,7 +34,9 @@ import org.mosad.seil0.projectlaogai.util.TimetableWeek
  * and lessonMap objects. It also contains the additional subjects logic.
  * All functions ro read or update cache files are located in the CacheController.
  *
- * TODO add configurable week to addSubject() and removeSubject(), updateAdditionalLessons()
+ * TODO
+ *  * add second week
+ *  * add configurable week to addSubject() and removeSubject(), updateAdditionalLessons()
  */
 class TimetableController {
 
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index bb8b2fc..6c9a224 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.6-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists