diff --git a/src/tsconfig.strictNullChecks.json b/src/tsconfig.strictNullChecks.json
index fdf3e4dc0df269dc3c32d097f098edf30dbeba33..52cbc4ad3f5cec4b56a7f9435d1b9c784a6c2f2b 100644
--- a/src/tsconfig.strictNullChecks.json
+++ b/src/tsconfig.strictNullChecks.json
@@ -682,6 +682,7 @@
 		"./vs/workbench/services/extensions/common/extensions.ts",
 		"./vs/workbench/services/extensions/common/extensionsRegistry.ts",
 		"./vs/workbench/services/extensions/electron-browser/cachedExtensionScanner.ts",
+		"./vs/workbench/services/extensions/electron-browser/extensionHostProfiler.ts",
 		"./vs/workbench/services/extensions/electron-browser/inactiveExtensionUrlHandler.ts",
 		"./vs/workbench/services/extensions/node/extensionDescriptionRegistry.ts",
 		"./vs/workbench/services/extensions/node/extensionManagementServerService.ts",
diff --git a/src/vs/workbench/services/extensions/common/extensions.ts b/src/vs/workbench/services/extensions/common/extensions.ts
index 4ee538b43ade1988dda3672f0ef0f3b3108bac1a..aa72b1b6ca102ea9332cd589093e51d40a5d2392 100644
--- a/src/vs/workbench/services/extensions/common/extensions.ts
+++ b/src/vs/workbench/services/extensions/common/extensions.ts
@@ -102,7 +102,7 @@ export interface IExtensionHostProfile {
 /**
  * Extension id or one of the four known program states.
  */
-export type ProfileSegmentId = string | 'idle' | 'program' | 'gc' | 'self';
+export type ProfileSegmentId = string | 'idle' | 'program' | 'gc' | 'self' | null;
 
 export class ActivationTimes {
 	constructor(
diff --git a/src/vs/workbench/services/extensions/electron-browser/extensionHostProfiler.ts b/src/vs/workbench/services/extensions/electron-browser/extensionHostProfiler.ts
index d7bdc83c64903e63acf3eabfa313dbcb73149413..329872540f6337c2c0702450173489a35be2f3b1 100644
--- a/src/vs/workbench/services/extensions/electron-browser/extensionHostProfiler.ts
+++ b/src/vs/workbench/services/extensions/electron-browser/extensionHostProfiler.ts
@@ -69,13 +69,13 @@ export class ExtensionHostProfiler {
 		}
 		visit(nodes[0], null);
 
-		let samples = profile.samples;
-		let timeDeltas = profile.timeDeltas;
+		const samples = profile.samples || [];
+		let timeDeltas = profile.timeDeltas || [];
 		let distilledDeltas: number[] = [];
 		let distilledIds: ProfileSegmentId[] = [];
 
 		let currSegmentTime = 0;
-		let currSegmentId: string = void 0;
+		let currSegmentId: string | undefined;
 		for (let i = 0; i < samples.length; i++) {
 			let id = samples[i];
 			let segmentId = idsToSegmentId.get(id);
@@ -84,7 +84,7 @@ export class ExtensionHostProfiler {
 					distilledIds.push(currSegmentId);
 					distilledDeltas.push(currSegmentTime);
 				}
-				currSegmentId = segmentId;
+				currSegmentId = segmentId || undefined;
 				currSegmentTime = 0;
 			}
 			currSegmentTime += timeDeltas[i];
@@ -93,9 +93,6 @@ export class ExtensionHostProfiler {
 			distilledIds.push(currSegmentId);
 			distilledDeltas.push(currSegmentTime);
 		}
-		idsToNodes = null;
-		idsToSegmentId = null;
-		searchTree = null;
 
 		return {
 			startTime: profile.startTime,