diff --git a/src/com/android/settings/datausage/DataUsageSummaryPreferenceController.java b/src/com/android/settings/datausage/DataUsageSummaryPreferenceController.java
index 44e5cf257d3..ccceae3ee14 100644
--- a/src/com/android/settings/datausage/DataUsageSummaryPreferenceController.java
+++ b/src/com/android/settings/datausage/DataUsageSummaryPreferenceController.java
@@ -17,7 +17,6 @@
 package com.android.settings.datausage;
 
 import android.app.Activity;
-import android.app.Fragment;
 import android.content.Context;
 import android.content.Intent;
 import android.net.NetworkPolicyManager;
@@ -27,7 +26,6 @@ import android.support.v7.preference.Preference;
 import android.telephony.SubscriptionInfo;
 import android.telephony.SubscriptionManager;
 import android.telephony.SubscriptionPlan;
-import android.telephony.TelephonyManager;
 import android.text.BidiFormatter;
 import android.text.Spannable;
 import android.text.SpannableString;
@@ -91,6 +89,8 @@ public class DataUsageSummaryPreferenceController extends BasePreferenceControll
      * -1 if no information is available.
      */
     private long mDataplanSize;
+    /** The "size" of the data usage bar, i.e. the amount of data its rhs end represents */
+    private long mDataBarSize;
     /** The number of bytes used since the start of the cycle. */
     private long mDataplanUse;
     /** The starting time of the billing cycle in ms since the epoch */
@@ -171,6 +171,7 @@ public class DataUsageSummaryPreferenceController extends BasePreferenceControll
     void setPlanValues(int dataPlanCount, long dataPlanSize, long dataPlanUse) {
         mDataplanCount = dataPlanCount;
         mDataplanSize = dataPlanSize;
+        mDataBarSize = dataPlanSize;
         mDataplanUse = dataPlanUse;
     }
 
@@ -237,13 +238,13 @@ public class DataUsageSummaryPreferenceController extends BasePreferenceControll
 
         summaryPreference.setUsageNumbers(mDataplanUse, mDataplanSize, mHasMobileData);
 
-        if (mDataplanSize <= 0) {
+        if (mDataBarSize <= 0) {
             summaryPreference.setChartEnabled(false);
         } else {
             summaryPreference.setChartEnabled(true);
             summaryPreference.setLabels(Formatter.formatFileSize(mContext, 0 /* sizeBytes */),
-                    Formatter.formatFileSize(mContext, mDataplanSize));
-            summaryPreference.setProgress(mDataplanUse / (float) mDataplanSize);
+                    Formatter.formatFileSize(mContext, mDataBarSize));
+            summaryPreference.setProgress(mDataplanUse / (float) mDataBarSize);
         }
         summaryPreference.setUsageInfo(mCycleEnd, mSnapshotTime, mCarrierName,
                 mDataplanCount, mManageSubscriptionIntent);
@@ -262,7 +263,8 @@ public class DataUsageSummaryPreferenceController extends BasePreferenceControll
         // reset data before overwriting
         mCarrierName = null;
         mDataplanCount = 0;
-        mDataplanSize = mDataInfoController.getSummaryLimit(info);
+        mDataplanSize = -1L;
+        mDataBarSize = mDataInfoController.getSummaryLimit(info);
         mDataplanUse = info.usageLevel;
         mCycleStart = info.cycleStart;
         mCycleEnd = info.cycleEnd;
@@ -278,8 +280,9 @@ public class DataUsageSummaryPreferenceController extends BasePreferenceControll
                 mDataplanCount = plans.size();
                 mDataplanSize = primaryPlan.getDataLimitBytes();
                 if (unlimited(mDataplanSize)) {
-                    mDataplanSize = 0L;
+                    mDataplanSize = -1L;
                 }
+                mDataBarSize = mDataplanSize;
                 mDataplanUse = primaryPlan.getDataUsageBytes();
 
                 RecurrenceRule rule = primaryPlan.getCycleRule();
diff --git a/tests/robotests/src/com/android/settings/datausage/DataUsageSummaryPreferenceControllerTest.java b/tests/robotests/src/com/android/settings/datausage/DataUsageSummaryPreferenceControllerTest.java
index 67caed4d393..60923576044 100644
--- a/tests/robotests/src/com/android/settings/datausage/DataUsageSummaryPreferenceControllerTest.java
+++ b/tests/robotests/src/com/android/settings/datausage/DataUsageSummaryPreferenceControllerTest.java
@@ -76,8 +76,6 @@ public class DataUsageSummaryPreferenceControllerTest {
     @Mock
     private DataUsageController mDataUsageController;
     @Mock
-    private DataUsageInfoController mDataInfoController;
-    @Mock
     private DataUsageSummaryPreference mSummaryPreference;
     @Mock
     private NetworkPolicyEditor mPolicyEditor;
@@ -96,6 +94,8 @@ public class DataUsageSummaryPreferenceControllerTest {
     @Mock
     private ConnectivityManager mConnectivityManager;
 
+    private DataUsageInfoController mDataInfoController;
+
     private FakeFeatureFactory mFactory;
     private Activity mActivity;
     private Context mContext;
@@ -113,6 +113,7 @@ public class DataUsageSummaryPreferenceControllerTest {
         when(mFactory.metricsFeatureProvider.getMetricsCategory(any(Object.class)))
                 .thenReturn(MetricsProto.MetricsEvent.SETTINGS_APP_NOTIF_CATEGORY);
         ShadowEntityHeaderController.setUseMock(mHeaderController);
+        mDataInfoController = new DataUsageInfoController();
 
         mActivity = spy(Robolectric.buildActivity(Activity.class).get());
         when(mActivity.getSystemService(TelephonyManager.class)).thenReturn(mTelephonyManager);