diff --git a/src/com/android/settings/deviceinfo/StorageDashboardFragment.java b/src/com/android/settings/deviceinfo/StorageDashboardFragment.java
index 4974f78..13b3d0b 100644
--- a/src/com/android/settings/deviceinfo/StorageDashboardFragment.java
+++ b/src/com/android/settings/deviceinfo/StorageDashboardFragment.java
@@ -131,7 +131,7 @@
             }
         }
 
-        mPreferenceController.onLoadFinished(mAppsResult.get(UserHandle.myUserId()));
+        mPreferenceController.onLoadFinished(mAppsResult, UserHandle.myUserId());
         updateSecondaryUserControllers(mSecondaryUsers, mAppsResult);
 
         // setLoading always causes a flicker, so let's avoid doing it.
diff --git a/src/com/android/settings/deviceinfo/StorageProfileFragment.java b/src/com/android/settings/deviceinfo/StorageProfileFragment.java
index 7e2d941..dee6793 100644
--- a/src/com/android/settings/deviceinfo/StorageProfileFragment.java
+++ b/src/com/android/settings/deviceinfo/StorageProfileFragment.java
@@ -120,7 +120,8 @@
     @Override
     public void onLoadFinished(Loader<SparseArray<AppsStorageResult>> loader,
             SparseArray<AppsStorageResult> result) {
-        mPreferenceController.onLoadFinished(scrubAppsFromResult(result.get(mUserId)));
+        scrubAppsFromResult(result.get(mUserId));
+        mPreferenceController.onLoadFinished(result, mUserId);
     }
 
     @Override
diff --git a/src/com/android/settings/deviceinfo/storage/StorageAsyncLoader.java b/src/com/android/settings/deviceinfo/storage/StorageAsyncLoader.java
index 8652804..74474b3 100644
--- a/src/com/android/settings/deviceinfo/storage/StorageAsyncLoader.java
+++ b/src/com/android/settings/deviceinfo/storage/StorageAsyncLoader.java
@@ -22,8 +22,8 @@
 
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
-import android.content.pm.UserInfo;
 import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.UserInfo;
 import android.os.UserHandle;
 import android.util.Log;
 import android.util.SparseArray;
@@ -87,45 +87,43 @@
                 stats = mStatsManager.getStatsForPackage(mUuid, app.packageName, myUser);
             } catch (NameNotFoundException | IOException e) {
                 // This may happen if the package was removed during our calculation.
-                Log.w("App unexpectedly not found", e);
+                Log.w(TAG, "App unexpectedly not found", e);
                 continue;
             }
 
-            long attributedAppSizeInBytes = stats.getDataBytes();
-            // This matches how the package manager calculates sizes -- by zeroing out code sizes of
-            // system apps which are not updated. My initial tests suggest that this results in the
-            // original code size being counted for updated system apps when they shouldn't, but
-            // I am not sure how to avoid this problem without specifically going in to find that
-            // code size.
-            if (!app.isSystemApp() || app.isUpdatedSystemApp()) {
-                attributedAppSizeInBytes += stats.getCodeBytes();
-            } else {
-                result.systemSize += stats.getCodeBytes();
+            long blamedSize = stats.getDataBytes() - stats.getCacheBytes();
+
+            // Only count app code against the current user; we don't want
+            // double-counting on multi-user devices.
+            if (userId == UserHandle.myUserId()) {
+                blamedSize += stats.getCodeBytes();
             }
+
             switch (app.category) {
                 case CATEGORY_GAME:
-                    result.gamesSize += attributedAppSizeInBytes;
+                    result.gamesSize += blamedSize;
                     break;
                 case CATEGORY_AUDIO:
-                    result.musicAppsSize += attributedAppSizeInBytes;
+                    result.musicAppsSize += blamedSize;
                     break;
                 case CATEGORY_VIDEO:
-                    result.videoAppsSize += attributedAppSizeInBytes;
+                    result.videoAppsSize += blamedSize;
                     break;
                 default:
                     // The deprecated game flag does not set the category.
                     if ((app.flags & ApplicationInfo.FLAG_IS_GAME) != 0) {
-                        result.gamesSize += attributedAppSizeInBytes;
+                        result.gamesSize += blamedSize;
                         break;
                     }
-                    result.otherAppsSize += attributedAppSizeInBytes;
+                    result.otherAppsSize += blamedSize;
                     break;
             }
         }
 
         Log.d(TAG, "Loading external stats");
         try {
-            result.externalStats = mStatsManager.getExternalStorageStats(mUuid, UserHandle.of(userId));
+            result.externalStats = mStatsManager.getExternalStorageStats(mUuid,
+                    UserHandle.of(userId));
         } catch (IOException e) {
             Log.w(TAG, e);
         }
@@ -142,7 +140,6 @@
         public long musicAppsSize;
         public long videoAppsSize;
         public long otherAppsSize;
-        public long systemSize;
         public StorageStatsSource.ExternalStorageStats externalStats;
     }
 
diff --git a/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceController.java b/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceController.java
index f8df375..cebd114 100644
--- a/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceController.java
+++ b/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceController.java
@@ -23,6 +23,7 @@
 import android.content.pm.PackageManager;
 import android.content.res.TypedArray;
 import android.graphics.drawable.Drawable;
+import android.net.TrafficStats;
 import android.os.Bundle;
 import android.os.UserHandle;
 import android.os.storage.VolumeInfo;
@@ -30,6 +31,7 @@
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceScreen;
 import android.util.Log;
+import android.util.SparseArray;
 
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
 import com.android.settings.R;
@@ -237,7 +239,10 @@
         setFilesPreferenceVisibility();
     }
 
-    public void onLoadFinished(StorageAsyncLoader.AppsStorageResult data) {
+    public void onLoadFinished(SparseArray<StorageAsyncLoader.AppsStorageResult> result,
+            int userId) {
+        final StorageAsyncLoader.AppsStorageResult data = result.get(userId);
+
         // TODO(b/35927909): Figure out how to split out apps which are only installed for work
         //       profiles in order to attribute those app's code bytes only to that profile.
         mPhotoPreference.setStorageSize(
@@ -248,23 +253,30 @@
         mMoviesPreference.setStorageSize(data.videoAppsSize, mTotalSize);
         mAppPreference.setStorageSize(data.otherAppsSize, mTotalSize);
 
-        long unattributedExternalBytes =
+        long otherExternalBytes =
                 data.externalStats.totalBytes
                         - data.externalStats.audioBytes
                         - data.externalStats.videoBytes
-                        - data.externalStats.imageBytes;
-        mFilePreference.setStorageSize(unattributedExternalBytes, mTotalSize);
+                        - data.externalStats.imageBytes
+                        - data.externalStats.appBytes;
+        mFilePreference.setStorageSize(otherExternalBytes, mTotalSize);
 
-        // We define the system size as everything we can't classify.
         if (mSystemPreference != null) {
-            mSystemPreference.setStorageSize(
-                    mUsedBytes
-                            - data.externalStats.totalBytes
-                            - data.musicAppsSize
-                            - data.gamesSize
-                            - data.videoAppsSize
-                            - data.otherAppsSize,
-                    mTotalSize);
+            // Everything else that hasn't already been attributed is tracked as
+            // belonging to system.
+            long attributedSize = 0;
+            for (int i = 0; i < result.size(); i++) {
+                final StorageAsyncLoader.AppsStorageResult otherData = result.valueAt(i);
+                attributedSize += otherData.gamesSize
+                        + otherData.musicAppsSize
+                        + otherData.videoAppsSize
+                        + otherData.otherAppsSize;
+                attributedSize += otherData.externalStats.totalBytes
+                        - otherData.externalStats.appBytes;
+            }
+
+            final long systemSize = Math.max(TrafficStats.GB_IN_BYTES, mUsedBytes - attributedSize);
+            mSystemPreference.setStorageSize(systemSize, mTotalSize);
         }
     }
 
diff --git a/tests/robotests/src/com/android/settings/applications/MusicViewHolderControllerTest.java b/tests/robotests/src/com/android/settings/applications/MusicViewHolderControllerTest.java
index 6440141..779e0b6 100644
--- a/tests/robotests/src/com/android/settings/applications/MusicViewHolderControllerTest.java
+++ b/tests/robotests/src/com/android/settings/applications/MusicViewHolderControllerTest.java
@@ -83,7 +83,7 @@
     @Test
     public void storageShouldRepresentStorageStatsQuery() throws Exception {
         when(mSource.getExternalStorageStats(any(String.class), any(UserHandle.class))).thenReturn(
-                new StorageStatsSource.ExternalStorageStats(1, 1, 0, 0));
+                new StorageStatsSource.ExternalStorageStats(1, 1, 0, 0, 0));
 
         mController.queryStats();
         mController.setupView(mHolder);
diff --git a/tests/robotests/src/com/android/settings/deviceinfo/StorageProfileFragmentTest.java b/tests/robotests/src/com/android/settings/deviceinfo/StorageProfileFragmentTest.java
index 8d48e63..03f15bb 100644
--- a/tests/robotests/src/com/android/settings/deviceinfo/StorageProfileFragmentTest.java
+++ b/tests/robotests/src/com/android/settings/deviceinfo/StorageProfileFragmentTest.java
@@ -17,6 +17,7 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.Matchers.anyInt;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 
@@ -31,11 +32,16 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.MockitoAnnotations;
 import org.robolectric.annotation.Config;
 
 @RunWith(SettingsRobolectricTestRunner.class)
 @Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
 public class StorageProfileFragmentTest {
+    @Captor
+    private ArgumentCaptor<SparseArray<StorageAsyncLoader.AppsStorageResult>> mCaptor;
+
     @Test
     public void verifyAppSizesAreZeroedOut() {
         StorageItemPreferenceController controller = mock(StorageItemPreferenceController.class);
@@ -45,18 +51,17 @@
         result.otherAppsSize = 200;
         result.gamesSize = 300;
         result.videoAppsSize = 400;
-        result.externalStats = new StorageStatsSource.ExternalStorageStats(6, 1, 2, 3);
+        result.externalStats = new StorageStatsSource.ExternalStorageStats(6, 1, 2, 3, 0);
         SparseArray<StorageAsyncLoader.AppsStorageResult> resultsArray = new SparseArray<>();
         resultsArray.put(0, result);
         fragment.setPreferenceController(controller);
 
         fragment.onLoadFinished(null, resultsArray);
 
-        ArgumentCaptor<StorageAsyncLoader.AppsStorageResult> resultCaptor = ArgumentCaptor.forClass(
-                StorageAsyncLoader.AppsStorageResult.class);
-        verify(controller).onLoadFinished(resultCaptor.capture());
+        MockitoAnnotations.initMocks(this);
+        verify(controller).onLoadFinished(mCaptor.capture(), anyInt());
 
-        StorageAsyncLoader.AppsStorageResult extractedResult = resultCaptor.getValue();
+        StorageAsyncLoader.AppsStorageResult extractedResult = mCaptor.getValue().get(0);
         assertThat(extractedResult.musicAppsSize).isEqualTo(0);
         assertThat(extractedResult.videoAppsSize).isEqualTo(0);
         assertThat(extractedResult.otherAppsSize).isEqualTo(0);
diff --git a/tests/robotests/src/com/android/settings/deviceinfo/storage/SecondaryUserControllerTest.java b/tests/robotests/src/com/android/settings/deviceinfo/storage/SecondaryUserControllerTest.java
index 32def69..dc1c286 100644
--- a/tests/robotests/src/com/android/settings/deviceinfo/storage/SecondaryUserControllerTest.java
+++ b/tests/robotests/src/com/android/settings/deviceinfo/storage/SecondaryUserControllerTest.java
@@ -168,7 +168,7 @@
                         MEGABYTE_IN_BYTES * 30,
                         MEGABYTE_IN_BYTES * 10,
                         MEGABYTE_IN_BYTES * 10,
-                        MEGABYTE_IN_BYTES * 10);
+                        MEGABYTE_IN_BYTES * 10, 0);
         result.put(10, userResult);
 
         mController.handleResult(result);
diff --git a/tests/robotests/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceControllerTest.java
index e8057a6..3ad3783 100644
--- a/tests/robotests/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/deviceinfo/storage/StorageItemPreferenceControllerTest.java
@@ -28,7 +28,6 @@
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
-
 import android.app.Fragment;
 import android.content.Context;
 import android.content.Intent;
@@ -36,6 +35,7 @@
 import android.os.UserHandle;
 import android.os.storage.VolumeInfo;
 import android.support.v7.preference.PreferenceScreen;
+import android.util.SparseArray;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.widget.LinearLayout;
@@ -275,22 +275,22 @@
         result.videoAppsSize = MEGABYTE_IN_BYTES * 160;
         result.musicAppsSize = MEGABYTE_IN_BYTES * 40;
         result.otherAppsSize = MEGABYTE_IN_BYTES * 90;
-        result.systemSize = MEGABYTE_IN_BYTES * 100; // This value is ignored and overridden now.
         result.externalStats =
                 new StorageStatsSource.ExternalStorageStats(
                         MEGABYTE_IN_BYTES * 500, // total
                         MEGABYTE_IN_BYTES * 100, // audio
                         MEGABYTE_IN_BYTES * 150, // video
-                        MEGABYTE_IN_BYTES * 200); // image
+                        MEGABYTE_IN_BYTES * 200, 0); // image
 
-        mController.onLoadFinished(result);
+        SparseArray<StorageAsyncLoader.AppsStorageResult> results = new SparseArray<>();
+        results.put(0, result);
+        mController.onLoadFinished(results, 0);
 
         assertThat(audio.getSummary().toString()).isEqualTo("0.14GB");
         assertThat(image.getSummary().toString()).isEqualTo("0.35GB");
         assertThat(games.getSummary().toString()).isEqualTo("0.08GB");
         assertThat(movies.getSummary().toString()).isEqualTo("0.16GB");
         assertThat(apps.getSummary().toString()).isEqualTo("0.09GB");
-        assertThat(system.getSummary().toString()).isEqualTo("0.10GB");
         assertThat(files.getSummary().toString()).isEqualTo("0.05GB");
     }
 
@@ -488,4 +488,4 @@
 
         verify(screen).addPreference(files);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/robotests/src/com/android/settings/deviceinfo/storage/UserProfileControllerTest.java b/tests/robotests/src/com/android/settings/deviceinfo/storage/UserProfileControllerTest.java
index 8b7110d..2199824 100644
--- a/tests/robotests/src/com/android/settings/deviceinfo/storage/UserProfileControllerTest.java
+++ b/tests/robotests/src/com/android/settings/deviceinfo/storage/UserProfileControllerTest.java
@@ -114,7 +114,7 @@
                         99 * MEGABYTE_IN_BYTES,
                         33 * MEGABYTE_IN_BYTES,
                         33 * MEGABYTE_IN_BYTES,
-                        33 * MEGABYTE_IN_BYTES);
+                        33 * MEGABYTE_IN_BYTES, 0);
         result.put(10, userResult);
 
         mController.handleResult(result);
@@ -141,4 +141,4 @@
         Preference preference = argumentCaptor.getValue();
         assertThat(preference.getIcon()).isEqualTo(drawable);
     }
-}
\ No newline at end of file
+}
diff --git a/tests/unit/src/com/android/settings/deviceinfo/storage/StorageAsyncLoaderTest.java b/tests/unit/src/com/android/settings/deviceinfo/storage/StorageAsyncLoaderTest.java
index 546ea4b..79a4595 100644
--- a/tests/unit/src/com/android/settings/deviceinfo/storage/StorageAsyncLoaderTest.java
+++ b/tests/unit/src/com/android/settings/deviceinfo/storage/StorageAsyncLoaderTest.java
@@ -133,9 +133,9 @@
         info.id = SECONDARY_USER_ID;
         mUsers.add(info);
         when(mSource.getExternalStorageStats(anyString(), eq(UserHandle.SYSTEM)))
-                .thenReturn(new StorageStatsSource.ExternalStorageStats(9, 2, 3, 4));
+                .thenReturn(new StorageStatsSource.ExternalStorageStats(9, 2, 3, 4, 0));
         when(mSource.getExternalStorageStats(anyString(), eq(new UserHandle(SECONDARY_USER_ID))))
-                .thenReturn(new StorageStatsSource.ExternalStorageStats(10, 3, 3, 4));
+                .thenReturn(new StorageStatsSource.ExternalStorageStats(10, 3, 3, 4, 0));
 
         SparseArray<StorageAsyncLoader.AppsStorageResult> result = mLoader.loadInBackground();
 
@@ -145,19 +145,6 @@
     }
 
     @Test
-    public void testSystemAppsBaseSizeIsAddedToSystem() throws Exception {
-        ApplicationInfo systemApp =
-                addPackage(PACKAGE_NAME_1, 100, 1, 10, ApplicationInfo.CATEGORY_UNDEFINED);
-        systemApp.flags = ApplicationInfo.FLAG_SYSTEM;
-
-        SparseArray<StorageAsyncLoader.AppsStorageResult> result = mLoader.loadInBackground();
-
-        assertThat(result.size()).isEqualTo(1);
-        assertThat(result.get(PRIMARY_USER_ID).otherAppsSize).isEqualTo(10L);
-        assertThat(result.get(PRIMARY_USER_ID).systemSize).isEqualTo(1L);
-    }
-
-    @Test
     public void testUpdatedSystemAppCodeSizeIsCounted() throws Exception {
         ApplicationInfo systemApp =
                 addPackage(PACKAGE_NAME_1, 100, 1, 10, ApplicationInfo.CATEGORY_UNDEFINED);