diff --git a/src/vs/editor/common/config/editorOptions.ts b/src/vs/editor/common/config/editorOptions.ts
index 1920af832ea8a085ca001df0d03c9dabecf4d353..b20246a3734acfe74f4547d286ccb3b8efefe78f 100644
--- a/src/vs/editor/common/config/editorOptions.ts
+++ b/src/vs/editor/common/config/editorOptions.ts
@@ -12,6 +12,7 @@ import { USUAL_WORD_SEPARATORS } from 'vs/editor/common/model/wordHelper';
 import { AccessibilitySupport } from 'vs/platform/accessibility/common/accessibility';
 import { IConfigurationPropertySchema } from 'vs/platform/configuration/common/configurationRegistry';
 import { IDimension } from 'vs/editor/common/editorCommon';
+import { IJSONSchema } from 'vs/base/common/jsonSchema';
 
 //#region typed options
 
@@ -1323,7 +1324,7 @@ class EditorGoToLocation extends BaseEditorOption<EditorOption.gotoLocation, GoT
 			multipleImplemenations: 'peek',
 			multipleReferences: 'peek',
 		};
-		const jsonSubset = {
+		const jsonSubset: IJSONSchema = {
 			type: 'string',
 			enum: ['peek', 'gotoAndPeek', 'goto'],
 			default: defaults.multiple,
diff --git a/src/vs/workbench/contrib/files/browser/files.contribution.ts b/src/vs/workbench/contrib/files/browser/files.contribution.ts
index 732e55455e72210dd01ebd29124091c55293f16e..4e4375262cac5110119275ca6b5e3620de0c9a2f 100644
--- a/src/vs/workbench/contrib/files/browser/files.contribution.ts
+++ b/src/vs/workbench/contrib/files/browser/files.contribution.ts
@@ -9,7 +9,7 @@ import * as nls from 'vs/nls';
 import { sep } from 'vs/base/common/path';
 import { SyncActionDescriptor, MenuId, MenuRegistry } from 'vs/platform/actions/common/actions';
 import { Registry } from 'vs/platform/registry/common/platform';
-import { IConfigurationRegistry, Extensions as ConfigurationExtensions, ConfigurationScope } from 'vs/platform/configuration/common/configurationRegistry';
+import { IConfigurationRegistry, Extensions as ConfigurationExtensions, ConfigurationScope, IConfigurationPropertySchema } from 'vs/platform/configuration/common/configurationRegistry';
 import { IWorkbenchActionRegistry, Extensions as ActionExtensions } from 'vs/workbench/common/actions';
 import { IWorkbenchContributionsRegistry, Extensions as WorkbenchExtensions, IWorkbenchContribution } from 'vs/workbench/common/contributions';
 import { IEditorInputFactory, EditorInput, IFileEditorInput, IEditorInputFactoryRegistry, Extensions as EditorInputExtensions } from 'vs/workbench/common/editor';
@@ -176,7 +176,7 @@ Registry.as<IWorkbenchContributionsRegistry>(WorkbenchExtensions.Workbench).regi
 // Configuration
 const configurationRegistry = Registry.as<IConfigurationRegistry>(ConfigurationExtensions.Configuration);
 
-const hotExitConfiguration = platform.isNative ?
+const hotExitConfiguration: IConfigurationPropertySchema = platform.isNative ?
 	{
 		'type': 'string',
 		'scope': ConfigurationScope.APPLICATION,
diff --git a/src/vs/workbench/contrib/remote/electron-browser/remote.contribution.ts b/src/vs/workbench/contrib/remote/electron-browser/remote.contribution.ts
index f8e1f3d3a133058ef701241f7bc518049214b454..39f1667ca883ebb8f2160ff12cfc062fe33d8663 100644
--- a/src/vs/workbench/contrib/remote/electron-browser/remote.contribution.ts
+++ b/src/vs/workbench/contrib/remote/electron-browser/remote.contribution.ts
@@ -38,6 +38,7 @@ import { IHostService } from 'vs/workbench/services/host/browser/host';
 import { RemoteConnectionState, Deprecated_RemoteAuthorityContext, RemoteFileDialogContext } from 'vs/workbench/browser/contextkeys';
 import { IDownloadService } from 'vs/platform/download/common/download';
 import { OpenLocalFileFolderCommand, OpenLocalFileCommand, OpenLocalFolderCommand, SaveLocalFileCommand } from 'vs/workbench/services/dialogs/browser/simpleFileDialog';
+import { IJSONSchema } from 'vs/base/common/jsonSchema';
 
 const WINDOW_ACTIONS_COMMAND_ID = 'workbench.action.remote.showMenu';
 const CLOSE_REMOTE_COMMAND_ID = 'workbench.action.remote.close';
@@ -365,7 +366,7 @@ workbenchContributionsRegistry.registerWorkbenchContribution(RemoteWindowActiveI
 workbenchContributionsRegistry.registerWorkbenchContribution(RemoteTelemetryEnablementUpdater, LifecyclePhase.Ready);
 workbenchContributionsRegistry.registerWorkbenchContribution(RemoteEmptyWorkbenchPresentation, LifecyclePhase.Starting);
 
-const extensionKindSchema = {
+const extensionKindSchema: IJSONSchema = {
 	type: 'string',
 	enum: [
 		'ui',
diff --git a/src/vs/workbench/services/preferences/common/preferencesModels.ts b/src/vs/workbench/services/preferences/common/preferencesModels.ts
index 59dcd697acf21e219d2ae001d4d93ce2cd5f6527..1406adf1750f42802f8fad350ff9cb30f70c9024 100644
--- a/src/vs/workbench/services/preferences/common/preferencesModels.ts
+++ b/src/vs/workbench/services/preferences/common/preferencesModels.ts
@@ -1117,7 +1117,7 @@ export function createValidator(prop: IConfigurationPropertySchema): (value: any
 			patternRegex = new RegExp(prop.pattern);
 		}
 
-		const type = Array.isArray(prop.type) ? prop.type : [prop.type];
+		const type: (string | undefined)[] = Array.isArray(prop.type) ? prop.type : [prop.type];
 		const canBeType = (t: string) => type.indexOf(t) > -1;
 
 		const isNullable = canBeType('null');