diff --git a/build/package.json b/build/package.json
index 1817f2c9345..96cb5414382 100644
--- a/build/package.json
+++ b/build/package.json
@@ -43,7 +43,7 @@
     "minimist": "^1.2.3",
     "request": "^2.85.0",
     "terser": "4.3.8",
-    "typescript": "^3.9.0-dev.20200327",
+    "typescript": "^3.9.0-dev.20200413",
     "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 e43e8eb3739..3bb4b7744c7 100644
--- a/build/yarn.lock
+++ b/build/yarn.lock
@@ -2458,10 +2458,10 @@ typescript@^3.0.1:
   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.20200327:
-  version "3.9.0-dev.20200327"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200327.tgz#52179aae816587f772a0526e91143760f2bee42f"
-  integrity sha512-/TWD/zPvhAcN2Toqx2NBQ+oDVGVj4iqupjWcUAwL45TfcODeHpzszneABR1b/EjHbtUObtLH40vy5Z6rdVvKzg==
+typescript@^3.9.0-dev.20200413:
+  version "3.9.0-dev.20200413"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200413.tgz#dd38331435f5c30867f19c94fe7cfc567ec13e20"
+  integrity sha512-wpPljcRc3uLTVpQ8mtKTkS42ipVnW1E7lU5iII+JSKaUDH1ymeo3duvMz8o2sCRUDoZR0SE0SLcinaZ1q4gD7A==
 
 typical@^4.0.0:
   version "4.0.0"
diff --git a/package.json b/package.json
index 0a077828c86..fdb689652a5 100644
--- a/package.json
+++ b/package.json
@@ -151,7 +151,7 @@
     "source-map": "^0.4.4",
     "style-loader": "^1.0.0",
     "ts-loader": "^4.4.2",
-    "typescript": "^3.9.0-dev.20200327",
+    "typescript": "^3.9.0-dev.20200413",
     "typescript-formatter": "7.1.0",
     "underscore": "^1.8.2",
     "vinyl": "^2.0.0",
diff --git a/src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts b/src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts
index 17127f65bb5..131c4cad98c 100644
--- a/src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts
+++ b/src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts
@@ -67,13 +67,11 @@ export class CodeCellViewModel extends BaseCellViewModel implements ICellViewMod
 		@ITextModelService private readonly _modelService: ITextModelService,
 	) {
 		super(viewType, notebookHandle, model, UUID.generateUuid());
-		if (this.model.onDidChangeOutputs) {
-			this._register(this.model.onDidChangeOutputs((splices) => {
-				this._outputCollection = new Array(this.model.outputs.length);
-				this._outputsTop = null;
-				this._onDidChangeOutputs.fire(splices);
-			}));
-		}
+		this._register(this.model.onDidChangeOutputs((splices) => {
+			this._outputCollection = new Array(this.model.outputs.length);
+			this._outputsTop = null;
+			this._onDidChangeOutputs.fire(splices);
+		}));
 
 		this._register(this.model.onDidChangeMetadata(() => {
 			this._onDidChangeMetadata.fire();
diff --git a/yarn.lock b/yarn.lock
index 418aa5426c8..2034e6576a0 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -9251,10 +9251,10 @@ typescript@^2.6.2:
   resolved "https://registry.yarnpkg.com/typescript/-/typescript-2.6.2.tgz#3c5b6fd7f6de0914269027f03c0946758f7673a4"
   integrity sha1-PFtv1/beCRQmkCfwPAlGdY92c6Q=
 
-typescript@^3.9.0-dev.20200327:
-  version "3.9.0-dev.20200327"
-  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200327.tgz#52179aae816587f772a0526e91143760f2bee42f"
-  integrity sha512-/TWD/zPvhAcN2Toqx2NBQ+oDVGVj4iqupjWcUAwL45TfcODeHpzszneABR1b/EjHbtUObtLH40vy5Z6rdVvKzg==
+typescript@^3.9.0-dev.20200413:
+  version "3.9.0-dev.20200413"
+  resolved "https://registry.yarnpkg.com/typescript/-/typescript-3.9.0-dev.20200413.tgz#dd38331435f5c30867f19c94fe7cfc567ec13e20"
+  integrity sha512-wpPljcRc3uLTVpQ8mtKTkS42ipVnW1E7lU5iII+JSKaUDH1ymeo3duvMz8o2sCRUDoZR0SE0SLcinaZ1q4gD7A==
 
 uc.micro@^1.0.1, uc.micro@^1.0.3:
   version "1.0.3"