diff --git a/.gitignore b/.gitignore
index c0ec93709..3215bf147 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,7 +22,8 @@ yarn-error.log
 
 ## types
 *.d.ts
-!packages/*/types/*
+!packages/**/*/types/**/*
+!packages/**/index.d.ts
 
 ## temp folders
 /.tmp/
diff --git a/packages/core/index.d.ts b/packages/core/index.d.ts
new file mode 100644
index 000000000..901842b0d
--- /dev/null
+++ b/packages/core/index.d.ts
@@ -0,0 +1,51 @@
+export { asyncAppend } from 'lit-html/directives/async-append.js';
+export { asyncReplace } from 'lit-html/directives/async-replace.js';
+export { cache } from 'lit-html/directives/cache.js';
+export { classMap } from 'lit-html/directives/class-map.js';
+export { guard } from 'lit-html/directives/guard.js';
+export { ifDefined } from 'lit-html/directives/if-defined.js';
+export { repeat } from 'lit-html/directives/repeat.js';
+export { styleMap } from 'lit-html/directives/style-map.js';
+export { unsafeHTML } from 'lit-html/directives/unsafe-html.js';
+export { until } from 'lit-html/directives/until.js';
+export { render as renderShady } from 'lit-html/lib/shady-render.js';
+export { ScopedElementsMixin } from '@open-wc/scoped-elements';
+export { dedupeMixin } from '@open-wc/dedupe-mixin';
+export { DelegateMixin } from './src/DelegateMixin.js';
+export { DisabledMixin } from './src/DisabledMixin.js';
+export { DisabledWithTabIndexMixin } from './src/DisabledWithTabIndexMixin.js';
+export { SlotMixin } from './src/SlotMixin.js';
+export { UpdateStylesMixin } from './src/UpdateStylesMixin.js';
+export { browserDetection } from './src/browserDetection.js';
+export {
+  css,
+  CSSResult,
+  customElement,
+  defaultConverter,
+  eventOptions,
+  LitElement,
+  notEqual,
+  property,
+  query,
+  queryAll,
+  supportsAdoptingStyleSheets,
+  unsafeCSS,
+  UpdatingElement,
+} from 'lit-element';
+export {
+  AttributePart,
+  BooleanAttributePart,
+  directive,
+  EventPart,
+  html,
+  isDirective,
+  isPrimitive,
+  noChange,
+  NodePart,
+  nothing,
+  PropertyPart,
+  render,
+  svg,
+  SVGTemplateResult,
+  TemplateResult,
+} from 'lit-html';
diff --git a/packages/core/test/DelegateMixin.test.js b/packages/core/test/DelegateMixin.test.js
index a9265bf7e..e459fd605 100644
--- a/packages/core/test/DelegateMixin.test.js
+++ b/packages/core/test/DelegateMixin.test.js
@@ -379,7 +379,7 @@ describe('DelegateMixin', () => {
   });
 
   it('works with connectedCallback', async () => {
-    class ConnectedElement extends DelegateMixin(HTMLElement) {
+    class ConnectedElement extends DelegateMixin(LitElement) {
       get delegations() {
         return {
           ...super.delegations,
diff --git a/packages/core/types/DelegateMixinTypes.d.ts b/packages/core/types/DelegateMixinTypes.d.ts
index 0840c3a64..3a7e7ad7a 100644
--- a/packages/core/types/DelegateMixinTypes.d.ts
+++ b/packages/core/types/DelegateMixinTypes.d.ts
@@ -1,4 +1,5 @@
 import { Constructor } from '@open-wc/dedupe-mixin';
+import { LitElement } from '../index.js';
 
 export type Delegations = {
   target: Function;
@@ -20,6 +21,9 @@ export declare class DelegateMixinHost {
   private __emptyEventListenerQueue(): void;
 
   private __emptyPropertiesQueue(): void;
+
+  connectedCallback(): void;
+  updated(changedProperties: import('lit-element').PropertyValues): void;
 }
 
 /**
@@ -44,7 +48,7 @@ export declare class DelegateMixinHost {
  *   `;
  * }
  */
-declare function DelegateMixinImplementation<T extends Constructor<HTMLElement>>(
+declare function DelegateMixinImplementation<T extends Constructor<LitElement>>(
   superclass: T,
 ): T & Constructor<DelegateMixinHost>;
 
diff --git a/packages/core/types/DisabledMixinTypes.d.ts b/packages/core/types/DisabledMixinTypes.d.ts
index ade1a1178..872c10efb 100644
--- a/packages/core/types/DisabledMixinTypes.d.ts
+++ b/packages/core/types/DisabledMixinTypes.d.ts
@@ -1,4 +1,5 @@
 import { Constructor } from '@open-wc/dedupe-mixin';
+import { LitElement } from 'lit-element';
 
 export declare class DisabledMixinHost {
   static get properties(): {
@@ -22,7 +23,7 @@ export declare class DisabledMixinHost {
   private __internalSetDisabled(value: boolean): void;
 }
 
-export declare function DisabledMixinImplementation<T extends Constructor<HTMLElement>>(
+export declare function DisabledMixinImplementation<T extends Constructor<LitElement>>(
   superclass: T,
 ): T & Constructor<DisabledMixinHost>;
 
diff --git a/packages/core/types/DisabledWithTabIndexMixinTypes.d.ts b/packages/core/types/DisabledWithTabIndexMixinTypes.d.ts
index 358005a3b..0e3083409 100644
--- a/packages/core/types/DisabledWithTabIndexMixinTypes.d.ts
+++ b/packages/core/types/DisabledWithTabIndexMixinTypes.d.ts
@@ -1,5 +1,6 @@
 import { Constructor } from '@open-wc/dedupe-mixin';
 import { DisabledMixinHost } from './DisabledMixinTypes';
+import { LitElement } from 'lit-element';
 export declare class DisabledWithTabIndexMixinHost {
   static get properties(): {
     tabIndex: {
@@ -20,9 +21,11 @@ export declare class DisabledWithTabIndexMixinHost {
   public retractRequestToBeDisabled(): void;
 
   private __internalSetTabIndex(value: boolean): void;
+
+  firstUpdated(changedProperties: import('lit-element').PropertyValues): void;
 }
 
-export declare function DisabledWithTabIndexMixinImplementation<T extends Constructor<HTMLElement>>(
+export declare function DisabledWithTabIndexMixinImplementation<T extends Constructor<LitElement>>(
   superclass: T,
 ): T & Constructor<DisabledWithTabIndexMixinHost> & Constructor<DisabledMixinHost>;
 
diff --git a/packages/core/types/SlotMixinTypes.d.ts b/packages/core/types/SlotMixinTypes.d.ts
index d911b267f..67e1c5844 100644
--- a/packages/core/types/SlotMixinTypes.d.ts
+++ b/packages/core/types/SlotMixinTypes.d.ts
@@ -25,6 +25,8 @@ export declare class SlotMixinHost {
    * @return {boolean} true if given slot name been created by SlotMixin
    */
   protected _isPrivateSlot(slotName: string): boolean;
+
+  connectedCallback(): void;
 }
 
 /**