diff --git a/src/com/android/messaging/ui/BlockedParticipantsActivity.java b/src/com/android/messaging/ui/BlockedParticipantsActivity.java
index b740264..8d79155 100644
--- a/src/com/android/messaging/ui/BlockedParticipantsActivity.java
+++ b/src/com/android/messaging/ui/BlockedParticipantsActivity.java
@@ -16,12 +16,10 @@
 
 package com.android.messaging.ui;
 
-import android.app.Fragment;
 import android.os.Bundle;
 import android.view.MenuItem;
 
 import com.android.messaging.R;
-import com.android.messaging.util.Assert;
 
 /**
  * Show a list of currently blocked participants.
@@ -36,11 +34,6 @@ public class BlockedParticipantsActivity extends BugleActionBarActivity {
         getSupportActionBar().setDisplayHomeAsUpEnabled(true);
     }
 
-    @Override
-    public void onAttachFragment(final Fragment fragment) {
-        Assert.isTrue(fragment instanceof BlockedParticipantsFragment);
-    }
-
     @Override
     public boolean onOptionsItemSelected(final MenuItem item) {
         switch (item.getItemId()) {
diff --git a/src/com/android/messaging/ui/VCardDetailActivity.java b/src/com/android/messaging/ui/VCardDetailActivity.java
index fecdc34..b9fb3d1 100644
--- a/src/com/android/messaging/ui/VCardDetailActivity.java
+++ b/src/com/android/messaging/ui/VCardDetailActivity.java
@@ -37,11 +37,13 @@ public class VCardDetailActivity extends BugleActionBarActivity {
 
     @Override
     public void onAttachFragment(final Fragment fragment) {
-        Assert.isTrue(fragment instanceof VCardDetailFragment);
-        final Uri vCardUri = getIntent().getParcelableExtra(UIIntents.UI_INTENT_EXTRA_VCARD_URI);
-        Assert.notNull(vCardUri);
-        final VCardDetailFragment vCardDetailFragment = (VCardDetailFragment) fragment;
-        vCardDetailFragment.setVCardUri(vCardUri);
+        if (fragment instanceof VCardDetailFragment) {
+            final Uri vCardUri =
+                    getIntent().getParcelableExtra(UIIntents.UI_INTENT_EXTRA_VCARD_URI);
+            Assert.notNull(vCardUri);
+            final VCardDetailFragment vCardDetailFragment = (VCardDetailFragment) fragment;
+            vCardDetailFragment.setVCardUri(vCardUri);
+        }
     }
 
     @Override