diff --git a/src/Explorer/Tree/AccessibleVerticalList.ts b/src/Explorer/Tree/AccessibleVerticalList.ts
index 818328a41..96db22df8 100644
--- a/src/Explorer/Tree/AccessibleVerticalList.ts
+++ b/src/Explorer/Tree/AccessibleVerticalList.ts
@@ -8,7 +8,7 @@ enum ScrollPosition {
 
 export class AccessibleVerticalList {
   private items: any[] = [];
-  private onSelect: (item: any) => void;
+  private onSelect?: (item: any) => void;
 
   public currentItemIndex: ko.Observable<number>;
   public currentItem: ko.Computed<any>;
@@ -42,7 +42,9 @@ export class AccessibleVerticalList {
       const targetElement = targetContainer
         .getElementsByClassName("accessibleListElement")
         .item(this.currentItemIndex());
-      this.scrollElementIntoContainerViewIfNeeded(targetElement, targetContainer, ScrollPosition.Top);
+      if (targetElement) {
+        this.scrollElementIntoContainerViewIfNeeded(targetElement, targetContainer, ScrollPosition.Top);
+      }
       return false;
     }
     if (event.keyCode === 40) {
@@ -52,7 +54,9 @@ export class AccessibleVerticalList {
       const targetElement = targetContainer
         .getElementsByClassName("accessibleListElement")
         .item(this.currentItemIndex());
-      this.scrollElementIntoContainerViewIfNeeded(targetElement, targetContainer, ScrollPosition.Bottom);
+      if (targetElement) {
+        this.scrollElementIntoContainerViewIfNeeded(targetElement, targetContainer, ScrollPosition.Top);
+      }
       return false;
     }
     return true;
diff --git a/tsconfig.strict.json b/tsconfig.strict.json
index 8b947e2c4..2a7da5bcd 100644
--- a/tsconfig.strict.json
+++ b/tsconfig.strict.json
@@ -59,6 +59,7 @@
     "./src/Explorer/Notebook/NotebookComponent/types.ts",
     "./src/Explorer/Notebook/NotebookContentItem.ts",
     "./src/Explorer/Notebook/NotebookUtil.ts",
+    "./src/Explorer/Tree/AccessibleVerticalList.ts",
     "./src/Explorer/Panes/PaneComponents.ts",
     "./src/Explorer/Panes/Tables/Validators/EntityPropertyNameValidator.ts",
     "./src/Explorer/Panes/Tables/Validators/EntityPropertyValidationCommon.ts",