diff --git a/js/ui/centerLayout.js b/js/ui/centerLayout.js
index eef124b89..19f64028e 100644
--- a/js/ui/centerLayout.js
+++ b/js/ui/centerLayout.js
@@ -50,9 +50,7 @@ const CenterLayout = new Lang.Class({
         let [left, center, right] = container.get_children();
 
         // Only support horizontal layouts for now.
-        let [leftMinWidth, leftNaturalWidth] = left.get_preferred_width(availWidth);
         let [centerMinWidth, centerNaturalWidth] = center.get_preferred_width(availWidth);
-        let [rightMinWidth, rightNaturalWidth] = right.get_preferred_width(availWidth);
 
         let sideWidth = (availWidth - centerNaturalWidth) / 2;
 
@@ -60,30 +58,36 @@ const CenterLayout = new Lang.Class({
         childBox.y1 = box.y1;
         childBox.y2 = box.y1 + availHeight;
 
-        let leftSide = Math.min(Math.floor(sideWidth), leftNaturalWidth);
-        if (rtl) {
-            childBox.x1 = availWidth - leftSide;
-            childBox.x2 = availWidth;
-        } else {
-            childBox.x1 = 0;
-            childBox.x2 = leftSide;
+        if (left) {
+            let [leftMinWidth, leftNaturalWidth] = left.get_preferred_width(availWidth);
+            let leftSide = Math.min(Math.floor(sideWidth), leftNaturalWidth);
+            if (rtl) {
+                childBox.x1 = availWidth - leftSide;
+                childBox.x2 = availWidth;
+            } else {
+                childBox.x1 = 0;
+                childBox.x2 = leftSide;
+            }
+            childBox.x1 += box.x1;
+            left.allocate(childBox, flags);
         }
-        childBox.x1 += box.x1;
-        left.allocate(childBox, flags);
 
         childBox.x1 = box.x1 + Math.ceil(sideWidth);
         childBox.x2 = childBox.x1 + centerNaturalWidth;
         center.allocate(childBox, flags);
 
-        let rightSide = Math.min(Math.floor(sideWidth), rightNaturalWidth);
-        if (rtl) {
-            childBox.x1 = 0;
-            childBox.x2 = rightSide;
-        } else {
-            childBox.x1 = availWidth - rightSide;
-            childBox.x2 = availWidth;
+        if (right) {
+            let [rightMinWidth, rightNaturalWidth] = right.get_preferred_width(availWidth);
+            let rightSide = Math.min(Math.floor(sideWidth), rightNaturalWidth);
+            if (rtl) {
+                childBox.x1 = 0;
+                childBox.x2 = rightSide;
+            } else {
+                childBox.x1 = availWidth - rightSide;
+                childBox.x2 = availWidth;
+            }
+            childBox.x1 += box.x1;
+            right.allocate(childBox, flags);
         }
-        childBox.x1 += box.x1;
-        right.allocate(childBox, flags);
     }
 });