diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 747388f4ec..fb1732b622 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -316,12 +316,6 @@
               android:theme="@style/TextSecure.LightTheme.Popup"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize" />
 
-    <activity android:name=".messagedetails.MessageDetailsActivity"
-              android:windowSoftInputMode="stateHidden"
-              android:launchMode="singleTask"
-              android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize"
-              android:theme="@style/Signal.DayNight.NoActionBar" />
-
     <activity android:name=".groups.ui.invitesandrequests.ManagePendingAndRequestingMembersActivity"
               android:configChanges="touchscreen|keyboard|keyboardHidden|orientation|screenLayout|screenSize|uiMode"
               android:theme="@style/Theme.Signal.DayNight.NoActionBar" />
diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java b/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java
index 3c1300ef91..3bbc159fcf 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationFragment.java
@@ -123,7 +123,7 @@ import org.thoughtcrime.securesms.jobs.MultiDeviceViewOnceOpenJob;
 import org.thoughtcrime.securesms.keyvalue.SignalStore;
 import org.thoughtcrime.securesms.linkpreview.LinkPreview;
 import org.thoughtcrime.securesms.longmessage.LongMessageFragment;
-import org.thoughtcrime.securesms.messagedetails.MessageDetailsActivity;
+import org.thoughtcrime.securesms.messagedetails.MessageDetailsFragment;
 import org.thoughtcrime.securesms.messagerequests.MessageRequestState;
 import org.thoughtcrime.securesms.messagerequests.MessageRequestViewModel;
 import org.thoughtcrime.securesms.mms.GlideApp;
@@ -1005,7 +1005,7 @@ public class ConversationFragment extends LoggingFragment implements Multiselect
   }
 
   private void handleDisplayDetails(ConversationMessage message) {
-    startActivity(MessageDetailsActivity.getIntentForMessageDetails(requireContext(), message.getMessageRecord(), recipient.getId(), threadId));
+    MessageDetailsFragment.create(message.getMessageRecord(), recipient.getId()).show(getChildFragmentManager(), null);
   }
 
   private void handleForwardMessageParts(Set<MultiselectPart> multiselectParts) {
diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationParentFragment.java b/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationParentFragment.java
index 63bbd53ecc..fde50e3e3e 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationParentFragment.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationParentFragment.java
@@ -212,7 +212,7 @@ import org.thoughtcrime.securesms.mediaoverview.MediaOverviewActivity;
 import org.thoughtcrime.securesms.mediasend.Media;
 import org.thoughtcrime.securesms.mediasend.MediaSendActivityResult;
 import org.thoughtcrime.securesms.mediasend.v2.MediaSelectionActivity;
-import org.thoughtcrime.securesms.messagedetails.MessageDetailsActivity;
+import org.thoughtcrime.securesms.messagedetails.MessageDetailsFragment;
 import org.thoughtcrime.securesms.messagerequests.MessageRequestState;
 import org.thoughtcrime.securesms.messagerequests.MessageRequestViewModel;
 import org.thoughtcrime.securesms.messagerequests.MessageRequestsBottomView;
@@ -3730,7 +3730,7 @@ public class ConversationParentFragment extends Fragment
   @Override
   public void onMessageWithErrorClicked(@NonNull MessageRecord messageRecord) {
     if (messageRecord.isIdentityMismatchFailure()) {
-      SafetyNumberChangeDialog.show(requireActivity(), messageRecord);
+      SafetyNumberChangeDialog.show(requireContext(), getChildFragmentManager(), messageRecord);
     } else if (messageRecord.hasFailedWithNetworkFailures()) {
       new AlertDialog.Builder(requireContext())
                      .setMessage(R.string.conversation_activity__message_could_not_be_sent)
@@ -3738,7 +3738,7 @@ public class ConversationParentFragment extends Fragment
                      .setPositiveButton(R.string.conversation_activity__send, (dialog, which) -> MessageSender.resend(requireContext(), messageRecord))
                      .show();
     } else {
-      startActivity(MessageDetailsActivity.getIntentForMessageDetails(requireContext(), messageRecord, messageRecord.getRecipient().getId(), messageRecord.getThreadId()));
+      MessageDetailsFragment.create(messageRecord, recipient.getId()).show(getChildFragmentManager(), null);
     }
   }
 
diff --git a/app/src/main/java/org/thoughtcrime/securesms/conversation/ui/error/SafetyNumberChangeDialog.java b/app/src/main/java/org/thoughtcrime/securesms/conversation/ui/error/SafetyNumberChangeDialog.java
index f2d7a0ec26..62e4098f8d 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/ui/error/SafetyNumberChangeDialog.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/ui/error/SafetyNumberChangeDialog.java
@@ -2,6 +2,7 @@ package org.thoughtcrime.securesms.conversation.ui.error;
 
 import android.app.Activity;
 import android.app.Dialog;
+import android.content.Context;
 import android.content.DialogInterface;
 import android.os.Bundle;
 import android.view.LayoutInflater;
@@ -77,9 +78,9 @@ public final class SafetyNumberChangeDialog extends DialogFragment implements Sa
     fragment.show(fragmentManager, SAFETY_NUMBER_DIALOG);
   }
 
-  public static void show(@NonNull FragmentActivity fragmentActivity, @NonNull MessageRecord messageRecord) {
+  public static void show(@NonNull Context context, @NonNull FragmentManager fragmentManager, @NonNull MessageRecord messageRecord) {
     List<String> ids = Stream.of(messageRecord.getIdentityKeyMismatches())
-                             .map(mismatch -> mismatch.getRecipientId(fragmentActivity).serialize())
+                             .map(mismatch -> mismatch.getRecipientId(context).serialize())
                              .distinct()
                              .toList();
 
@@ -90,7 +91,7 @@ public final class SafetyNumberChangeDialog extends DialogFragment implements Sa
     arguments.putInt(CONTINUE_TEXT_RESOURCE_EXTRA, R.string.safety_number_change_dialog__send_anyway);
     SafetyNumberChangeDialog fragment = new SafetyNumberChangeDialog();
     fragment.setArguments(arguments);
-    fragment.show(fragmentActivity.getSupportFragmentManager(), SAFETY_NUMBER_DIALOG);
+    fragment.show(fragmentManager, SAFETY_NUMBER_DIALOG);
   }
 
   public static void showForCall(@NonNull FragmentManager fragmentManager, @NonNull RecipientId recipientId) {
diff --git a/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsActivity.java b/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsFragment.java
similarity index 63%
rename from app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsActivity.java
rename to app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsFragment.java
index 910724a6fe..17d7508e26 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsActivity.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsFragment.java
@@ -1,18 +1,17 @@
 package org.thoughtcrime.securesms.messagedetails;
 
-import android.content.Context;
-import android.content.Intent;
 import android.os.Bundle;
-import android.view.MenuItem;
 import android.view.View;
 import android.widget.FrameLayout;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.fragment.app.DialogFragment;
 import androidx.lifecycle.ViewModelProviders;
 import androidx.recyclerview.widget.RecyclerView;
 
-import org.thoughtcrime.securesms.PassphraseRequiredActivity;
 import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.components.FullScreenDialogFragment;
 import org.thoughtcrime.securesms.components.recyclerview.ToolbarShadowAnimationHelper;
 import org.thoughtcrime.securesms.conversation.colors.Colorizer;
 import org.thoughtcrime.securesms.conversation.colors.RecyclerViewColorizer;
@@ -27,17 +26,14 @@ import org.thoughtcrime.securesms.messagedetails.MessageDetailsViewModel.Factory
 import org.thoughtcrime.securesms.mms.GlideApp;
 import org.thoughtcrime.securesms.mms.GlideRequests;
 import org.thoughtcrime.securesms.recipients.RecipientId;
-import org.thoughtcrime.securesms.util.DynamicNoActionBarTheme;
-import org.thoughtcrime.securesms.util.DynamicTheme;
 
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
-public final class MessageDetailsActivity extends PassphraseRequiredActivity {
+public final class MessageDetailsFragment extends FullScreenDialogFragment {
 
   private static final String MESSAGE_ID_EXTRA = "message_id";
-  private static final String THREAD_ID_EXTRA  = "thread_id";
   private static final String TYPE_EXTRA       = "type";
   private static final String RECIPIENT_EXTRA  = "recipient_id";
 
@@ -47,60 +43,53 @@ public final class MessageDetailsActivity extends PassphraseRequiredActivity {
   private Colorizer               colorizer;
   private RecyclerViewColorizer   recyclerViewColorizer;
 
-  private DynamicTheme dynamicTheme = new DynamicNoActionBarTheme();
+  public static @NonNull DialogFragment create(@NonNull MessageRecord message, @NonNull RecipientId recipientId) {
+    DialogFragment dialogFragment = new MessageDetailsFragment();
+    Bundle         args           = new Bundle();
 
-  public static @NonNull Intent getIntentForMessageDetails(@NonNull Context context, @NonNull MessageRecord message, @NonNull RecipientId recipientId, long threadId) {
-    Intent intent = new Intent(context, MessageDetailsActivity.class);
-    intent.putExtra(MESSAGE_ID_EXTRA, message.getId());
-    intent.putExtra(THREAD_ID_EXTRA, threadId);
-    intent.putExtra(TYPE_EXTRA, message.isMms() ? MmsSmsDatabase.MMS_TRANSPORT : MmsSmsDatabase.SMS_TRANSPORT);
-    intent.putExtra(RECIPIENT_EXTRA, recipientId);
-    return intent;
+    args.putLong(MESSAGE_ID_EXTRA, message.getId());
+    args.putString(TYPE_EXTRA, message.isMms() ? MmsSmsDatabase.MMS_TRANSPORT : MmsSmsDatabase.SMS_TRANSPORT);
+    args.putParcelable(RECIPIENT_EXTRA, recipientId);
+
+    dialogFragment.setArguments(args);
+
+    return dialogFragment;
   }
 
   @Override
-  protected void onPreCreate() {
-    dynamicTheme.onCreate(this);
+  protected int getTitle() {
+    return R.string.AndroidManifest__message_details;
   }
 
   @Override
-  protected void onCreate(Bundle savedInstanceState, boolean ready) {
-    super.onCreate(savedInstanceState, ready);
-    setContentView(R.layout.message_details_activity);
+  protected int getDialogLayoutResource() {
+    return R.layout.message_details_fragment;
+  }
 
+  @Override
+  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
     glideRequests = GlideApp.with(this);
 
-    initializeList();
+    initializeList(view);
     initializeViewModel();
-    initializeActionBar();
-    initializeVideoPlayer();
+    initializeVideoPlayer(view);
   }
 
   @Override
-  protected void onResume() {
+  public void onResume() {
     super.onResume();
-    dynamicTheme.onResume(this);
     adapter.resumeMessageExpirationTimer();
   }
 
   @Override
-  protected void onPause() {
+  public void onPause() {
     super.onPause();
     adapter.pauseMessageExpirationTimer();
   }
 
-  @Override
-  public boolean onOptionsItemSelected(MenuItem item) {
-    if (item.getItemId() == android.R.id.home) {
-      onBackPressed();
-      return true;
-    }
-    return super.onOptionsItemSelected(item);
-  }
-
-  private void initializeList() {
-    RecyclerView  list          = findViewById(R.id.message_details_list);
-    View          toolbarShadow = findViewById(R.id.toolbar_shadow);
+  private void initializeList(@NonNull View view) {
+    RecyclerView  list          = view.findViewById(R.id.message_details_list);
+    View          toolbarShadow = view.findViewById(R.id.toolbar_shadow);
 
     colorizer             = new Colorizer();
     adapter               = new MessageDetailsAdapter(this, glideRequests, colorizer, this::onErrorClicked);
@@ -112,15 +101,15 @@ public final class MessageDetailsActivity extends PassphraseRequiredActivity {
   }
 
   private void initializeViewModel() {
-    final RecipientId recipientId = getIntent().getParcelableExtra(RECIPIENT_EXTRA);
-    final String      type        = getIntent().getStringExtra(TYPE_EXTRA);
-    final Long        messageId   = getIntent().getLongExtra(MESSAGE_ID_EXTRA, -1);
+    final RecipientId recipientId = requireArguments().getParcelable(RECIPIENT_EXTRA);
+    final String      type        = requireArguments().getString(TYPE_EXTRA);
+    final Long        messageId   = requireArguments().getLong(MESSAGE_ID_EXTRA, -1);
     final Factory     factory     = new Factory(recipientId, type, messageId);
 
     viewModel = ViewModelProviders.of(this, factory).get(MessageDetailsViewModel.class);
     viewModel.getMessageDetails().observe(this, details -> {
       if (details == null) {
-        finish();
+        dismissAllowingStateLoss();
       } else {
         adapter.submitList(convertToRows(details));
       }
@@ -128,21 +117,15 @@ public final class MessageDetailsActivity extends PassphraseRequiredActivity {
     viewModel.getRecipient().observe(this, recipient -> recyclerViewColorizer.setChatColors(recipient.getChatColors()));
   }
 
-  private void initializeVideoPlayer() {
-    FrameLayout                          videoContainer = findViewById(R.id.video_container);
-    RecyclerView                         recyclerView   = findViewById(R.id.message_details_list);
-    List<GiphyMp4ProjectionPlayerHolder> holders        = GiphyMp4ProjectionPlayerHolder.injectVideoViews(this, getLifecycle(), videoContainer, 1);
+  private void initializeVideoPlayer(@NonNull View view) {
+    FrameLayout                          videoContainer = view.findViewById(R.id.video_container);
+    RecyclerView                         recyclerView   = view.findViewById(R.id.message_details_list);
+    List<GiphyMp4ProjectionPlayerHolder> holders        = GiphyMp4ProjectionPlayerHolder.injectVideoViews(requireContext(), getLifecycle(), videoContainer, 1);
     GiphyMp4ProjectionRecycler           callback       = new GiphyMp4ProjectionRecycler(holders);
 
     GiphyMp4PlaybackController.attach(recyclerView, callback, 1);
   }
 
-  private void initializeActionBar() {
-    setSupportActionBar(findViewById(R.id.toolbar));
-    requireSupportActionBar().setDisplayHomeAsUpEnabled(true);
-    requireSupportActionBar().setTitle(R.string.AndroidManifest__message_details);
-  }
-
   private List<MessageDetailsViewState<?>> convertToRows(MessageDetails details) {
     List<MessageDetailsViewState<?>> list = new ArrayList<>();
 
@@ -175,6 +158,6 @@ public final class MessageDetailsActivity extends PassphraseRequiredActivity {
   }
 
   private void onErrorClicked(@NonNull MessageRecord messageRecord) {
-    SafetyNumberChangeDialog.show(this, messageRecord);
+    SafetyNumberChangeDialog.show(requireContext(), getChildFragmentManager(), messageRecord);
   }
 }
diff --git a/app/src/main/res/layout/message_details_activity.xml b/app/src/main/res/layout/message_details_fragment.xml
similarity index 62%
rename from app/src/main/res/layout/message_details_activity.xml
rename to app/src/main/res/layout/message_details_fragment.xml
index 175e47c19b..39b62fe81c 100644
--- a/app/src/main/res/layout/message_details_activity.xml
+++ b/app/src/main/res/layout/message_details_fragment.xml
@@ -1,24 +1,10 @@
 <?xml version="1.0" encoding="utf-8"?>
 <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:background="@color/signal_background_primary">
 
-    <androidx.appcompat.widget.Toolbar
-        android:id="@+id/toolbar"
-        android:layout_width="match_parent"
-        android:layout_height="56dp"
-        android:theme="?attr/settingsToolbarStyle"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent"
-        app:navigationIcon="@drawable/ic_arrow_left_24"
-        app:titleTextAppearance="@style/Signal.Text.Title"
-        app:navigationContentDescription="@string/DSLSettingsToolbar__navigate_up"
-        tools:title="Message Details" />
-
     <FrameLayout
         android:id="@+id/video_container"
         android:layout_width="0dp"
@@ -26,17 +12,17 @@
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/toolbar"  />
+        app:layout_constraintTop_toTopOf="parent" />
 
     <androidx.recyclerview.widget.RecyclerView
         android:id="@+id/message_details_list"
         android:layout_width="0dp"
         android:layout_height="0dp"
+        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/toolbar"
-        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager" />
+        app:layout_constraintTop_toTopOf="parent" />
 
     <View
         android:id="@+id/toolbar_shadow"
@@ -46,6 +32,6 @@
         android:background="@drawable/toolbar_shadow"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toBottomOf="@id/toolbar" />
+        app:layout_constraintTop_toTopOf="parent" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file