diff --git a/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseFragmentTest.java b/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseFragmentTest.java
index bb25edc..0008f93 100644
--- a/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseFragmentTest.java
+++ b/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseFragmentTest.java
@@ -25,7 +25,6 @@
 import android.content.Intent;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
-import android.support.test.filters.Suppress;
 import android.support.test.rule.ActivityTestRule;
 import android.support.test.runner.AndroidJUnit4;
 import android.support.v17.leanback.widget.ItemBridgeAdapter;
@@ -41,7 +40,6 @@
 import org.junit.runner.RunWith;
 import org.mockito.Mockito;
 
-@Suppress
 @MediumTest
 @RunWith(AndroidJUnit4.class)
 public class BrowseFragmentTest {
diff --git a/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseSupportFragmentTest.java b/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseSupportFragmentTest.java
index 699cef1..c7862c9 100644
--- a/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseSupportFragmentTest.java
+++ b/v17/leanback/tests/java/android/support/v17/leanback/app/BrowseSupportFragmentTest.java
@@ -28,7 +28,6 @@
 import android.content.Intent;
 import android.support.test.InstrumentationRegistry;
 import android.support.test.filters.MediumTest;
-import android.support.test.filters.Suppress;
 import android.support.test.rule.ActivityTestRule;
 import android.support.test.runner.AndroidJUnit4;
 import android.support.v17.leanback.widget.ItemBridgeAdapter;
@@ -44,7 +43,6 @@
 import org.junit.runner.RunWith;
 import org.mockito.Mockito;
 
-@Suppress
 @MediumTest
 @RunWith(AndroidJUnit4.class)
 public class BrowseSupportFragmentTest {
diff --git a/v7/recyclerview/src/android/support/v7/widget/GapWorker.java b/v7/recyclerview/src/android/support/v7/widget/GapWorker.java
index 2ed205f..9392ee2 100644
--- a/v7/recyclerview/src/android/support/v7/widget/GapWorker.java
+++ b/v7/recyclerview/src/android/support/v7/widget/GapWorker.java
@@ -107,8 +107,7 @@
         @Override
         public void addPosition(int layoutPosition, int pixelDistance) {
             if (layoutPosition < 0) {
-                // temporary fix for b/35708283
-                return;
+                throw new IllegalArgumentException("Layout positions must be non-negative");
             }
 
             if (pixelDistance < 0) {
@@ -150,6 +149,7 @@
             if (mPrefetchArray != null) {
                 Arrays.fill(mPrefetchArray, -1);
             }
+            mCount = 0;
         }
     }
 
@@ -226,6 +226,11 @@
         int totalTaskIndex = 0;
         for (int i = 0; i < viewCount; i++) {
             RecyclerView view = mRecyclerViews.get(i);
+            if (view.getWindowVisibility() != View.VISIBLE) {
+                // Invisible view, don't bother prefetching
+                continue;
+            }
+
             LayoutPrefetchRegistryImpl prefetchRegistry = view.mPrefetchRegistry;
             final int viewVelocity = Math.abs(prefetchRegistry.mPrefetchDx)
                     + Math.abs(prefetchRegistry.mPrefetchDy);
diff --git a/v7/recyclerview/tests/src/android/support/v7/widget/GapWorkerTest.java b/v7/recyclerview/tests/src/android/support/v7/widget/GapWorkerTest.java
index 5d08931..9158161 100644
--- a/v7/recyclerview/tests/src/android/support/v7/widget/GapWorkerTest.java
+++ b/v7/recyclerview/tests/src/android/support/v7/widget/GapWorkerTest.java
@@ -43,6 +43,43 @@
     }
 
     @Test
+    public void registrySimple() {
+        GapWorker.LayoutPrefetchRegistryImpl registry = new GapWorker.LayoutPrefetchRegistryImpl();
+        registry.addPosition(0, 0);
+        registry.addPosition(2, 0);
+        registry.addPosition(3, 0);
+        assertTrue(registry.lastPrefetchIncludedPosition(0));
+        assertFalse(registry.lastPrefetchIncludedPosition(1));
+        assertTrue(registry.lastPrefetchIncludedPosition(2));
+        assertTrue(registry.lastPrefetchIncludedPosition(3));
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void registryNegativeLayout() {
+        GapWorker.LayoutPrefetchRegistryImpl registry = new GapWorker.LayoutPrefetchRegistryImpl();
+        registry.addPosition(-1, 0);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void registryNegativeDistance() {
+        GapWorker.LayoutPrefetchRegistryImpl registry = new GapWorker.LayoutPrefetchRegistryImpl();
+        registry.addPosition(0, -1);
+    }
+
+    @Test
+    public void registryResetCorrectly() {
+        GapWorker.LayoutPrefetchRegistryImpl registry = new GapWorker.LayoutPrefetchRegistryImpl();
+        registry.addPosition(0, 0);
+        assertFalse(registry.lastPrefetchIncludedPosition(-1));
+        assertTrue(registry.lastPrefetchIncludedPosition(0));
+
+        registry.clearPrefetchPositions();
+
+        assertFalse(registry.lastPrefetchIncludedPosition(-1));
+        assertFalse(registry.lastPrefetchIncludedPosition(0));
+    }
+
+    @Test
     public void taskOrderViewPresence() {
         ArrayList<GapWorker.Task> list = new ArrayList<>();
         list.add(new GapWorker.Task());