diff --git a/build/package.json b/build/package.json
index 2abecaa1279..36a8b905ed8 100644
--- a/build/package.json
+++ b/build/package.json
@@ -43,7 +43,7 @@
     "minimist": "^1.2.0",
     "request": "^2.85.0",
     "terser": "4.3.8",
-    "typescript": "3.9.0-dev.20200304",
+    "typescript": "^3.9.0-dev.20200313",
     "vsce": "1.48.0",
     "vscode-telemetry-extractor": "^1.5.4",
     "xml2js": "^0.4.17"
diff --git a/build/yarn.lock b/build/yarn.lock
index ef17978a534..26886e94794 100644
--- a/build/yarn.lock
+++ b/build/yarn.lock
@@ -2453,16 +2453,16 @@ typed-rest-client@^0.9.0:
     tunnel "0.0.4"
     underscore "1.8.3"
 
-typescript@3.9.0-dev.20200304:
-  version "3.9.0-dev.20200304"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200304.tgz#3cc35357eff29dc5604b4fa56d6597e13daf86ed"
-  integrity sha512-eUip/GgJmjp4qtHiJDxVhE5SDDiPzBUg7KBAFUgb7HgL/tv10JAHej7fnS1i+7xrq1eDtbkJyPaYOVnhL9db7Q==
-
 typescript@^3.0.1:
   version "3.5.3"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.5.3.tgz#c830f657f93f1ea846819e929092f5fe5983e977"
   integrity sha512-ACzBtm/PhXBDId6a6sDJfroT2pOWt/oOnk4/dElG5G33ZL776N3Y6/6bKZJBFpd+b05F3Ct9qDjMeJmRWtE2/g==
 
+typescript@^3.9.0-dev.20200313:
+  version "3.9.0-dev.20200313"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200313.tgz#f66aeb2c08268f2b1fc6d1d96e15554c6e7ed29b"
+  integrity sha512-85/IJPm1nEUbQDxK3aN+svIy4X3kPcAipihB3704NY1HXncJ1daNLJW1OktOacb8tD/URpIGs9nMgbUrKvglGg==
+
 typical@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/typical/-/typical-4.0.0.tgz#cbeaff3b9d7ae1e2bbfaf5a4e6f11eccfde94fc4"
diff --git a/package.json b/package.json
index dcc6b7a6341..308165d4aa4 100644
--- a/package.json
+++ b/package.json
@@ -150,7 +150,7 @@
     "source-map": "^0.4.4",
     "style-loader": "^1.0.0",
     "ts-loader": "^4.4.2",
-    "typescript": "3.9.0-dev.20200304",
+    "typescript": "^3.9.0-dev.20200313",
     "typescript-formatter": "7.1.0",
     "underscore": "^1.8.2",
     "vinyl": "^2.0.0",
diff --git a/src/vs/base/parts/tree/browser/treeViewModel.ts b/src/vs/base/parts/tree/browser/treeViewModel.ts
index 823f0bb0a9d..b78c4d8184f 100644
--- a/src/vs/base/parts/tree/browser/treeViewModel.ts
+++ b/src/vs/base/parts/tree/browser/treeViewModel.ts
@@ -45,8 +45,7 @@ export class HeightMap {
 			totalSize = viewItem.top + viewItem.height;
 		}
 
-		let boundSplice = this.heightMap.splice.bind(this.heightMap, i, 0);
-
+		const startingIndex = i;
 		let itemsToInsert: IViewItem[] = [];
 
 		while (item = iterator.next()) {
@@ -58,7 +57,7 @@ export class HeightMap {
 			sizeDiff += viewItem.height;
 		}
 
-		boundSplice.apply(this.heightMap, itemsToInsert);
+		this.heightMap.splice(startingIndex, 0, ...itemsToInsert);
 
 		for (j = i; j < this.heightMap.length; j++) {
 			viewItem = this.heightMap[j];
diff --git a/yarn.lock b/yarn.lock
index c2f11789a2a..49f82d4de93 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9220,16 +9220,16 @@ typescript-formatter@7.1.0:
     commandpost "^1.0.0"
     editorconfig "^0.15.0"
 
-typescript@3.9.0-dev.20200304:
-  version "3.9.0-dev.20200304"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200304.tgz#3cc35357eff29dc5604b4fa56d6597e13daf86ed"
-  integrity sha512-eUip/GgJmjp4qtHiJDxVhE5SDDiPzBUg7KBAFUgb7HgL/tv10JAHej7fnS1i+7xrq1eDtbkJyPaYOVnhL9db7Q==
-
 typescript@^2.6.2:
   version "2.6.2"
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.6.2.tgz#3c5b6fd7f6de0914269027f03c0946758f7673a4"
   integrity sha1-PFtv1/beCRQmkCfwPAlGdY92c6Q=
 
+typescript@^3.9.0-dev.20200313:
+  version "3.9.0-dev.20200313"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200313.tgz#f66aeb2c08268f2b1fc6d1d96e15554c6e7ed29b"
+  integrity sha512-85/IJPm1nEUbQDxK3aN+svIy4X3kPcAipihB3704NY1HXncJ1daNLJW1OktOacb8tD/URpIGs9nMgbUrKvglGg==
+
 uc.micro@^1.0.1, uc.micro@^1.0.3:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/uc.micro/-/uc.micro-1.0.3.tgz#7ed50d5e0f9a9fb0a573379259f2a77458d50192"