diff --git a/gradle.properties b/gradle.properties
index 6bb950f0c..128f9ec93 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -18,5 +18,5 @@ android.enableJetifier=true
 android.useAndroidX=true
 org.gradle.gradle-args=--max-workers=32
 android.defaults.buildfeatures.buildconfig=true
-android.nonTransitiveRClass=false
+android.nonTransitiveRClass=true
 android.nonFinalResIds=false
\ No newline at end of file
diff --git a/src/main/java/de/monocles/chat/ReadMoreTextView.java b/src/main/java/de/monocles/chat/ReadMoreTextView.java
index 2ded73b7b..3f8474855 100644
--- a/src/main/java/de/monocles/chat/ReadMoreTextView.java
+++ b/src/main/java/de/monocles/chat/ReadMoreTextView.java
@@ -76,7 +76,7 @@ public class ReadMoreTextView extends AppCompatTextView {
         this.trimExpandedText = getResources().getString(resourceIdTrimExpandedText);
         this.trimLines = typedArray.getInt(R.styleable.ReadMoreTextView_trimLines, DEFAULT_TRIM_LINES);
         this.colorClickableText = typedArray.getColor(R.styleable.ReadMoreTextView_colorClickableText,
-                ContextCompat.getColor(context, R.color.colorAccent));
+                ContextCompat.getColor(context, androidx.appcompat.R.color.abc_btn_colored_borderless_text_material));
         this.showTrimExpandedText =
                 typedArray.getBoolean(R.styleable.ReadMoreTextView_showTrimExpandedText, DEFAULT_SHOW_TRIM_EXPANDED_TEXT);
         this.readMore = typedArray.getBoolean(R.styleable.ReadMoreTextView_readMore, DEFAULT_READ_MORE);
diff --git a/src/main/java/eu/siacs/conversations/services/NotificationService.java b/src/main/java/eu/siacs/conversations/services/NotificationService.java
index 982fcf28d..0560549d3 100644
--- a/src/main/java/eu/siacs/conversations/services/NotificationService.java
+++ b/src/main/java/eu/siacs/conversations/services/NotificationService.java
@@ -1115,7 +1115,7 @@ public class NotificationService {
             color = account.getColor(false);
         } else {
             TypedValue typedValue = new TypedValue();
-            mXmppConnectionService.getTheme().resolveAttribute(R.attr.colorPrimary, typedValue, true);
+            mXmppConnectionService.getTheme().resolveAttribute(androidx.appcompat.R.attr.colorPrimary, typedValue, true);
             color = typedValue.data;
         }
         mBuilder.setColor(color);
diff --git a/src/main/java/eu/siacs/conversations/ui/forms/FormFieldWrapper.java b/src/main/java/eu/siacs/conversations/ui/forms/FormFieldWrapper.java
index 18cec2770..8e66f36c2 100644
--- a/src/main/java/eu/siacs/conversations/ui/forms/FormFieldWrapper.java
+++ b/src/main/java/eu/siacs/conversations/ui/forms/FormFieldWrapper.java
@@ -9,7 +9,6 @@ import android.view.View;
 
 import java.util.List;
 
-import eu.siacs.conversations.R;
 import eu.siacs.conversations.ui.util.StyledAttributes;
 import eu.siacs.conversations.xmpp.forms.Field;
 
@@ -58,7 +57,7 @@ public abstract class FormFieldWrapper {
             int start = label.length();
             int end = label.length() + 2;
             spannableString.setSpan(new StyleSpan(android.graphics.Typeface.BOLD), start, end, 0);
-            spannableString.setSpan(new ForegroundColorSpan(StyledAttributes.getColor(context, R.attr.colorAccent)), start, end, 0);
+            spannableString.setSpan(new ForegroundColorSpan(StyledAttributes.getColor(context, androidx.appcompat.R.attr.colorAccent)), start, end, 0);
         }
         return spannableString;
     }
diff --git a/src/main/java/eu/siacs/conversations/ui/util/CustomTab.java b/src/main/java/eu/siacs/conversations/ui/util/CustomTab.java
index fa083dc94..57fc7aeb7 100644
--- a/src/main/java/eu/siacs/conversations/ui/util/CustomTab.java
+++ b/src/main/java/eu/siacs/conversations/ui/util/CustomTab.java
@@ -17,8 +17,8 @@ public class CustomTab {
         tabBuilder.setShowTitle(true);
         tabBuilder.setUrlBarHidingEnabled(false);
         tabBuilder.setDefaultColorSchemeParams(new CustomTabColorSchemeParams.Builder()
-                .setToolbarColor(StyledAttributes.getColor(context, R.attr.colorPrimary))
-                .setSecondaryToolbarColor(StyledAttributes.getColor(context, R.attr.colorPrimaryDark))
+                .setToolbarColor(StyledAttributes.getColor(context, androidx.appcompat.R.attr.colorPrimary))
+                .setSecondaryToolbarColor(StyledAttributes.getColor(context, androidx.appcompat.R.attr.colorPrimaryDark))
                 .build());
         tabBuilder.setColorScheme(dark ? CustomTabsIntent.COLOR_SCHEME_DARK : CustomTabsIntent.COLOR_SCHEME_LIGHT);
         tabBuilder.setShareState(CustomTabsIntent.SHARE_STATE_ON);
diff --git a/src/main/java/eu/siacs/conversations/ui/widget/SwipeRefreshListFragment.java b/src/main/java/eu/siacs/conversations/ui/widget/SwipeRefreshListFragment.java
index b1ef6165a..5f5d6a8cf 100644
--- a/src/main/java/eu/siacs/conversations/ui/widget/SwipeRefreshListFragment.java
+++ b/src/main/java/eu/siacs/conversations/ui/widget/SwipeRefreshListFragment.java
@@ -26,7 +26,6 @@ import android.widget.ListView;
 import androidx.fragment.app.ListFragment;
 import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
 
-import eu.siacs.conversations.R;
 import eu.siacs.conversations.ui.util.StyledAttributes;
 
 /**
@@ -57,7 +56,7 @@ public class SwipeRefreshListFragment extends ListFragment {
 
         final Context context = getActivity();
         if (context != null) {
-            mSwipeRefreshLayout.setColorSchemeColors(StyledAttributes.getColor(context, R.attr.colorAccent));
+            mSwipeRefreshLayout.setColorSchemeColors(StyledAttributes.getColor(context, androidx.appcompat.R.attr.colorAccent));
         }
 
         if (onRefreshListener != null) {
diff --git a/src/main/res/values/strings.xml b/src/main/res/values/strings.xml
index def4300ab..ea672f593 100644
--- a/src/main/res/values/strings.xml
+++ b/src/main/res/values/strings.xml
@@ -1351,4 +1351,5 @@
     <string name="hide_notification">Hide notification</string>
     <string name="log_out">Log out</string>
     <string name="log_in">Log in</string>
+    <string name="unknown">Unknown</string>
 </resources>