diff --git a/src/components/ha-checkbox.ts b/src/components/ha-checkbox.ts
index c4ef540352f5..232d663b13a0 100644
--- a/src/components/ha-checkbox.ts
+++ b/src/components/ha-checkbox.ts
@@ -1,8 +1,9 @@
-import { Constructor, customElement, CSSResult, css } from "lit-element";
+import { customElement, CSSResult, css } from "lit-element";
 import "@material/mwc-checkbox";
 // tslint:disable-next-line
 import { Checkbox } from "@material/mwc-checkbox";
 import { style } from "@material/mwc-checkbox/mwc-checkbox-css";
+import { Constructor } from "../types";
 // tslint:disable-next-line
 const MwcCheckbox = customElements.get("mwc-checkbox") as Constructor<Checkbox>;
 
diff --git a/src/components/ha-fab.ts b/src/components/ha-fab.ts
index f7ffee55fefe..2003ac0c41ca 100644
--- a/src/components/ha-fab.ts
+++ b/src/components/ha-fab.ts
@@ -1,12 +1,8 @@
-import {
-  classMap,
-  html,
-  customElement,
-  Constructor,
-} from "@material/mwc-base/base-element";
+import { classMap, html, customElement } from "@material/mwc-base/base-element";
 import { ripple } from "@material/mwc-ripple/ripple-directive.js";
 
 import "@material/mwc-fab";
+import { Constructor } from "../types";
 // tslint:disable-next-line
 import { Fab } from "@material/mwc-fab";
 // tslint:disable-next-line
diff --git a/src/components/ha-icon.ts b/src/components/ha-icon.ts
index 2e2a6ba848af..5d71f214ed79 100644
--- a/src/components/ha-icon.ts
+++ b/src/components/ha-icon.ts
@@ -1,4 +1,5 @@
-import { Constructor } from "lit-element";
+import { Constructor } from "../types";
+
 import "@polymer/iron-icon/iron-icon";
 // Not duplicate, this is for typing.
 // tslint:disable-next-line
diff --git a/src/components/ha-paper-dropdown-menu.ts b/src/components/ha-paper-dropdown-menu.ts
index bed3e0ea1079..72f2f6b15c9e 100644
--- a/src/components/ha-paper-dropdown-menu.ts
+++ b/src/components/ha-paper-dropdown-menu.ts
@@ -1,6 +1,6 @@
 import "@polymer/paper-dropdown-menu/paper-dropdown-menu";
-import { Constructor } from "lit-element";
 import { PolymerElement } from "@polymer/polymer";
+import { Constructor } from "../types";
 
 const paperDropdownClass = customElements.get(
   "paper-dropdown-menu"
diff --git a/src/components/ha-paper-icon-button-arrow-next.ts b/src/components/ha-paper-icon-button-arrow-next.ts
index 6bf526ec2e43..f0d473038526 100644
--- a/src/components/ha-paper-icon-button-arrow-next.ts
+++ b/src/components/ha-paper-icon-button-arrow-next.ts
@@ -1,5 +1,5 @@
-import { Constructor } from "lit-element";
 import "@polymer/paper-icon-button/paper-icon-button";
+import { Constructor } from "../types";
 // Not duplicate, this is for typing.
 // tslint:disable-next-line
 import { PaperIconButtonElement } from "@polymer/paper-icon-button/paper-icon-button";
diff --git a/src/components/ha-paper-icon-button-arrow-prev.ts b/src/components/ha-paper-icon-button-arrow-prev.ts
index dd6378acadb5..d79c8c66f4e3 100644
--- a/src/components/ha-paper-icon-button-arrow-prev.ts
+++ b/src/components/ha-paper-icon-button-arrow-prev.ts
@@ -1,5 +1,5 @@
-import { Constructor } from "lit-element";
 import "@polymer/paper-icon-button/paper-icon-button";
+import { Constructor } from "../types";
 // Not duplicate, this is for typing.
 // tslint:disable-next-line
 import { PaperIconButtonElement } from "@polymer/paper-icon-button/paper-icon-button";
diff --git a/src/components/ha-paper-icon-button-next.ts b/src/components/ha-paper-icon-button-next.ts
index e3038e5a0061..cca612de4f34 100644
--- a/src/components/ha-paper-icon-button-next.ts
+++ b/src/components/ha-paper-icon-button-next.ts
@@ -1,5 +1,5 @@
-import { Constructor } from "lit-element";
 import "@polymer/paper-icon-button/paper-icon-button";
+import { Constructor } from "../types";
 // Not duplicate, this is for typing.
 // tslint:disable-next-line
 import { PaperIconButtonElement } from "@polymer/paper-icon-button/paper-icon-button";
diff --git a/src/components/ha-paper-icon-button-prev.ts b/src/components/ha-paper-icon-button-prev.ts
index 396482be4b83..ca4c32ff1ce5 100644
--- a/src/components/ha-paper-icon-button-prev.ts
+++ b/src/components/ha-paper-icon-button-prev.ts
@@ -1,5 +1,5 @@
-import { Constructor } from "lit-element";
 import "@polymer/paper-icon-button/paper-icon-button";
+import { Constructor } from "../types";
 // Not duplicate, this is for typing.
 // tslint:disable-next-line
 import { PaperIconButtonElement } from "@polymer/paper-icon-button/paper-icon-button";
diff --git a/src/components/ha-switch.ts b/src/components/ha-switch.ts
index 53b8cf122992..b31909c499ff 100644
--- a/src/components/ha-switch.ts
+++ b/src/components/ha-switch.ts
@@ -1,8 +1,9 @@
-import { Constructor, customElement, CSSResult, css, query } from "lit-element";
+import { customElement, CSSResult, css, query } from "lit-element";
 import "@material/mwc-switch";
 import { style } from "@material/mwc-switch/mwc-switch-css";
 // tslint:disable-next-line
 import { Switch } from "@material/mwc-switch";
+import { Constructor } from "../types";
 // tslint:disable-next-line
 const MwcSwitch = customElements.get("mwc-switch") as Constructor<Switch>;
 
diff --git a/src/mixins/lit-localize-lite-mixin.ts b/src/mixins/lit-localize-lite-mixin.ts
index 59a90f536460..c99d32c5a81f 100644
--- a/src/mixins/lit-localize-lite-mixin.ts
+++ b/src/mixins/lit-localize-lite-mixin.ts
@@ -1,45 +1,20 @@
-import {
-  Constructor,
-  LitElement,
-  PropertyDeclarations,
-  PropertyValues,
-} from "lit-element";
-import { getLocalLanguage } from "../util/hass-translation";
-import { localizeLiteBaseMixin } from "./localize-lite-base-mixin";
+import { LitElement, PropertyValues, property } from "lit-element";
+import { getLocalLanguage, getTranslation } from "../util/hass-translation";
 import { computeLocalize, LocalizeFunc } from "../common/translations/localize";
+import { Constructor, Resources } from "../types";
 
 const empty = () => "";
 
-interface LitLocalizeLiteMixin {
-  language: string;
-  resources: {};
-  translationFragment: string;
-  localize: LocalizeFunc;
-}
-
-export const litLocalizeLiteMixin = <T extends LitElement>(
-  superClass: Constructor<T>
-): Constructor<T & LitLocalizeLiteMixin> =>
-  // @ts-ignore
-  class extends localizeLiteBaseMixin(superClass) {
-    // Decorators not possible in anonymous classes
-    // And also, we cannot declare the variable without overriding the Lit setter.
-    static get properties(): PropertyDeclarations {
-      return {
-        localize: {},
-        language: {},
-        resources: {},
-        translationFragment: {},
-      };
-    }
-
-    constructor() {
-      super();
-      // This will prevent undefined errors if called before connected to DOM.
-      this.localize = empty;
-      // Use browser language setup before login.
-      this.language = getLocalLanguage();
-    }
+export const litLocalizeLiteMixin = <T extends Constructor<LitElement>>(
+  superClass: T
+) => {
+  class LitLocalizeLiteClass extends superClass {
+    // Initialized to empty will prevent undefined errors if called before connected to DOM.
+    @property() public localize: LocalizeFunc = empty;
+    @property() public resources?: Resources;
+    // Use browser language setup before login.
+    @property() public language?: string = getLocalLanguage();
+    @property() public translationFragment?: string;
 
     public connectedCallback(): void {
       super.connectedCallback();
@@ -51,7 +26,7 @@ export const litLocalizeLiteMixin = <T extends LitElement>(
       );
     }
 
-    public updated(changedProperties: PropertyValues) {
+    protected updated(changedProperties: PropertyValues) {
       super.updated(changedProperties);
       if (
         changedProperties.has("language") ||
@@ -64,4 +39,38 @@ export const litLocalizeLiteMixin = <T extends LitElement>(
         );
       }
     }
-  };
+
+    protected async _initializeLocalizeLite() {
+      if (this.resources) {
+        return;
+      }
+
+      if (!this.translationFragment) {
+        // In dev mode, we will issue a warning if after a second we are still
+        // not configured correctly.
+        if (__DEV__) {
+          setTimeout(
+            () =>
+              !this.resources &&
+              // tslint:disable-next-line
+              console.error(
+                "Forgot to pass in resources or set translationFragment for",
+                this.nodeName
+              ),
+            1000
+          );
+        }
+        return;
+      }
+
+      const { language, data } = await getTranslation(
+        this.translationFragment!,
+        this.language!
+      );
+      this.resources = {
+        [language]: data,
+      };
+    }
+  }
+  return LitLocalizeLiteClass;
+};
diff --git a/src/mixins/localize-lite-base-mixin.ts b/src/mixins/localize-lite-base-mixin.ts
deleted file mode 100644
index 83fbd612afe4..000000000000
--- a/src/mixins/localize-lite-base-mixin.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- * Lite base mixin to add localization without depending on the Hass object.
- */
-import { getTranslation } from "../util/hass-translation";
-import { Resources } from "../types";
-
-/**
- * @polymerMixin
- */
-export const localizeLiteBaseMixin = (superClass) =>
-  class extends superClass {
-    public resources?: Resources;
-    public language?: string;
-    public translationFragment?: string;
-
-    protected _initializeLocalizeLite() {
-      if (this.resources) {
-        return;
-      }
-
-      if (!this.translationFragment) {
-        // In dev mode, we will issue a warning if after a second we are still
-        // not configured correctly.
-        if (__DEV__) {
-          setTimeout(
-            () =>
-              !this.resources &&
-              // tslint:disable-next-line
-              console.error(
-                "Forgot to pass in resources or set translationFragment for",
-                this.nodeName
-              ),
-            1000
-          );
-        }
-        return;
-      }
-
-      this._downloadResources();
-    }
-
-    private async _downloadResources() {
-      const { language, data } = await getTranslation(
-        this.translationFragment!,
-        this.language!
-      );
-      this.resources = {
-        [language]: data,
-      };
-    }
-  };
diff --git a/src/mixins/localize-lite-mixin.ts b/src/mixins/localize-lite-mixin.ts
deleted file mode 100644
index 8fcf11297297..000000000000
--- a/src/mixins/localize-lite-mixin.ts
+++ /dev/null
@@ -1,51 +0,0 @@
-/**
- * Lite mixin to add localization without depending on the Hass object.
- */
-import { dedupingMixin } from "@polymer/polymer/lib/utils/mixin";
-import { getLocalLanguage } from "../util/hass-translation";
-import { localizeLiteBaseMixin } from "./localize-lite-base-mixin";
-import { computeLocalize } from "../common/translations/localize";
-
-/**
- * @polymerMixin
- */
-export const localizeLiteMixin = dedupingMixin(
-  (superClass) =>
-    class extends localizeLiteBaseMixin(superClass) {
-      static get properties() {
-        return {
-          language: {
-            type: String,
-            // Use browser language setup before login.
-            value: getLocalLanguage(),
-          },
-          resources: Object,
-          // The fragment to load.
-          translationFragment: String,
-          /**
-           * Translates a string to the current `language`. Any parameters to the
-           * string should be passed in order, as follows:
-           * `localize(stringKey, param1Name, param1Value, param2Name, param2Value)`
-           */
-          localize: {
-            type: Function,
-            computed: "__computeLocalize(language, resources, formats)",
-          },
-        };
-      }
-
-      public ready() {
-        super.ready();
-        this._initializeLocalizeLite();
-      }
-
-      protected __computeLocalize(language, resources, formats?) {
-        return computeLocalize(
-          this.constructor.prototype,
-          language,
-          resources,
-          formats
-        );
-      }
-    }
-);
diff --git a/src/mixins/provide-hass-lit-mixin.ts b/src/mixins/provide-hass-lit-mixin.ts
index 3b45ecedbe32..fb9d1b3e930f 100644
--- a/src/mixins/provide-hass-lit-mixin.ts
+++ b/src/mixins/provide-hass-lit-mixin.ts
@@ -1,5 +1,5 @@
-import { UpdatingElement, Constructor, PropertyValues } from "lit-element";
-import { HomeAssistant } from "../types";
+import { UpdatingElement, PropertyValues } from "lit-element";
+import { HomeAssistant, Constructor } from "../types";
 
 export interface ProvideHassElement {
   provideHass(element: HTMLElement);
@@ -7,9 +7,9 @@ export interface ProvideHassElement {
 
 /* tslint:disable */
 
-export const ProvideHassLitMixin = <T extends UpdatingElement>(
-  superClass: Constructor<T>
-): Constructor<T & ProvideHassElement> =>
+export const ProvideHassLitMixin = <T extends Constructor<UpdatingElement>>(
+  superClass: T
+) =>
   // @ts-ignore
   class extends superClass {
     protected hass!: HomeAssistant;
diff --git a/src/mixins/subscribe-mixin.ts b/src/mixins/subscribe-mixin.ts
index 95b31e5eeb9d..350055d232e3 100644
--- a/src/mixins/subscribe-mixin.ts
+++ b/src/mixins/subscribe-mixin.ts
@@ -1,32 +1,21 @@
-import {
-  LitElement,
-  Constructor,
-  PropertyValues,
-  PropertyDeclarations,
-} from "lit-element";
+import { LitElement, PropertyValues, property } from "lit-element";
 import { UnsubscribeFunc } from "home-assistant-js-websocket";
+import { HomeAssistant, Constructor } from "../types";
 
 export interface HassSubscribeElement {
   hassSubscribe(): UnsubscribeFunc[];
 }
 
 /* tslint:disable-next-line */
-export const SubscribeMixin = <T extends LitElement>(
-  superClass: Constructor<T>
-): Constructor<T & HassSubscribeElement> =>
-  // @ts-ignore
-  class extends superClass {
+export const SubscribeMixin = <T extends Constructor<LitElement>>(
+  superClass: T
+) => {
+  class SubscribeClass extends superClass {
+    @property() public hass?: HomeAssistant;
+
     /* tslint:disable-next-line */
     private __unsubs?: UnsubscribeFunc[];
 
-    // Decorators not possible in anonymous classes
-    // And also, we cannot declare the variable without overriding the Lit setter.
-    static get properties(): PropertyDeclarations {
-      return {
-        hass: {},
-      };
-    }
-
     public connectedCallback() {
       super.connectedCallback();
       this.__checkSubscribed();
@@ -57,11 +46,12 @@ export const SubscribeMixin = <T extends LitElement>(
       if (
         this.__unsubs !== undefined ||
         !((this as unknown) as Element).isConnected ||
-        // @ts-ignore
         this.hass === undefined
       ) {
         return;
       }
       this.__unsubs = this.hassSubscribe();
     }
-  };
+  }
+  return SubscribeClass;
+};
diff --git a/src/state/auth-mixin.ts b/src/state/auth-mixin.ts
index c97730ac3f02..baf012cfdc9e 100644
--- a/src/state/auth-mixin.ts
+++ b/src/state/auth-mixin.ts
@@ -1,8 +1,8 @@
 import { clearState } from "../util/ha-pref-storage";
 import { askWrite } from "../common/auth/token_storage";
 import { subscribeUser, userCollection } from "../data/ws-user";
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
+import { Constructor } from "../types";
 
 declare global {
   // for fire event
@@ -11,7 +11,7 @@ declare global {
   }
 }
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
diff --git a/src/state/connection-mixin.ts b/src/state/connection-mixin.ts
index eb439c813568..5712b1439253 100644
--- a/src/state/connection-mixin.ts
+++ b/src/state/connection-mixin.ts
@@ -17,12 +17,12 @@ import hassCallApi from "../util/hass-call-api";
 import { subscribePanels } from "../data/ws-panels";
 import { forwardHaptic } from "../data/haptics";
 import { fireEvent } from "../common/dom/fire_event";
-import { Constructor, LitElement } from "lit-element";
+import { Constructor } from "../types";
 import { HassBaseEl } from "./hass-base-mixin";
 import { broadcastConnectionStatus } from "../data/connection-status";
 
-export const connectionMixin = (
-  superClass: Constructor<LitElement & HassBaseEl>
+export const connectionMixin = <T extends Constructor<HassBaseEl>>(
+  superClass: T
 ) =>
   class extends superClass {
     protected initializeHass(auth: Auth, conn: Connection) {
@@ -90,13 +90,13 @@ export const connectionMixin = (
           conn.sendMessage(msg);
         },
         // For messages that expect a response
-        callWS: <T>(msg) => {
+        callWS: <R>(msg) => {
           if (__DEV__) {
             // tslint:disable-next-line: no-console
             console.log("Sending", msg);
           }
 
-          const resp = conn.sendMessagePromise<T>(msg);
+          const resp = conn.sendMessagePromise<R>(msg);
 
           if (__DEV__) {
             resp.then(
diff --git a/src/state/dialog-manager-mixin.ts b/src/state/dialog-manager-mixin.ts
index 5fcae876a376..f6e525b5fc99 100644
--- a/src/state/dialog-manager-mixin.ts
+++ b/src/state/dialog-manager-mixin.ts
@@ -1,7 +1,7 @@
-import { Constructor, LitElement } from "lit-element";
 import { HASSDomEvent } from "../common/dom/fire_event";
 import { HassBaseEl } from "./hass-base-mixin";
 import { makeDialogManager, showDialog } from "../dialogs/make-dialog-manager";
+import { Constructor } from "../types";
 
 interface RegisterDialogParams {
   dialogShowEvent: keyof HASSDomEvents;
@@ -20,8 +20,8 @@ declare global {
   }
 }
 
-export const dialogManagerMixin = (
-  superClass: Constructor<LitElement & HassBaseEl>
+export const dialogManagerMixin = <T extends Constructor<HassBaseEl>>(
+  superClass: T
 ) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
diff --git a/src/state/disconnect-toast-mixin.ts b/src/state/disconnect-toast-mixin.ts
index a36ec359ff81..e2b6aeb14e09 100644
--- a/src/state/disconnect-toast-mixin.ts
+++ b/src/state/disconnect-toast-mixin.ts
@@ -1,8 +1,8 @@
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import { showToast } from "../util/toast";
+import { Constructor } from "../types";
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
diff --git a/src/state/haptic-mixin.ts b/src/state/haptic-mixin.ts
index 44c02664c9e1..3fe9adea6947 100644
--- a/src/state/haptic-mixin.ts
+++ b/src/state/haptic-mixin.ts
@@ -1,8 +1,8 @@
-import { Constructor, LitElement, PropertyValues } from "lit-element";
+import { PropertyValues } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 
 import { HapticType } from "../data/haptics";
-import { HomeAssistant } from "../types";
+import { HomeAssistant, Constructor } from "../types";
 import { HASSDomEvent } from "../common/dom/fire_event";
 import { storeState } from "../util/ha-pref-storage";
 
@@ -35,7 +35,7 @@ const handleHaptic = (hapticTypeEvent: HASSDomEvent<HapticType>) => {
   navigator.vibrate(hapticPatterns[hapticTypeEvent.detail]);
 };
 
-export const hapticMixin = (superClass: Constructor<LitElement & HassBaseEl>) =>
+export const hapticMixin = <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps: PropertyValues) {
       super.firstUpdated(changedProps);
diff --git a/src/state/hass-base-mixin.ts b/src/state/hass-base-mixin.ts
index 81c4e0689916..34bd9eebaec6 100644
--- a/src/state/hass-base-mixin.ts
+++ b/src/state/hass-base-mixin.ts
@@ -1,77 +1,51 @@
-import {
-  Constructor,
-  // @ts-ignore
-  property,
-  PropertyDeclarations,
-} from "lit-element";
-import { Auth, Connection } from "home-assistant-js-websocket";
+import { LitElement, property } from "lit-element";
 import { HomeAssistant } from "../types";
+import { Auth, Connection } from "home-assistant-js-websocket";
 
-/* tslint:disable */
-
-export class HassBaseEl {
-  protected hass?: HomeAssistant;
+export class HassBaseEl extends LitElement {
+  @property() public hass?: HomeAssistant;
   protected _pendingHass: Partial<HomeAssistant> = {};
-  protected initializeHass(_auth: Auth, _conn: Connection) {}
-  protected hassConnected() {}
-  protected hassReconnected() {}
-  protected hassDisconnected() {}
-  protected hassChanged(_hass: HomeAssistant, _oldHass?: HomeAssistant) {}
-  protected panelUrlChanged(_newPanelUrl: string) {}
-  public provideHass(_el: HTMLElement) {}
-  protected _updateHass(_obj: Partial<HomeAssistant>) {}
+  // tslint:disable-next-line: variable-name
+  private __provideHass: HTMLElement[] = [];
+
+  public provideHass(el) {
+    this.__provideHass.push(el);
+    el.hass = this.hass;
+  }
+
+  protected initializeHass(_auth: Auth, _conn: Connection) {
+    // implemented in connection-mixin
+    // tslint:disable-next-line
+  }
+
+  // Exists so all methods can safely call super method
+  protected hassConnected() {
+    // tslint:disable-next-line
+  }
+
+  protected hassReconnected() {
+    // tslint:disable-next-line
+  }
+
+  protected hassDisconnected() {
+    // tslint:disable-next-line
+  }
+
+  protected panelUrlChanged(_newPanelUrl) {
+    // tslint:disable-next-line
+  }
+
+  protected hassChanged(hass, _oldHass) {
+    this.__provideHass.forEach((el) => {
+      (el as any).hass = hass;
+    });
+  }
+
+  protected _updateHass(obj: Partial<HomeAssistant>) {
+    if (!this.hass) {
+      this._pendingHass = { ...this._pendingHass, ...obj };
+      return;
+    }
+    this.hass = { ...this.hass, ...obj };
+  }
 }
-
-export default <T>(superClass: Constructor<T>): Constructor<T & HassBaseEl> =>
-  // @ts-ignore
-  class extends superClass {
-    protected _pendingHass: Partial<HomeAssistant> = {};
-    private __provideHass: HTMLElement[] = [];
-
-    // Decorators not possible in anonymous classes
-    // And also, we cannot declare the variable without overriding the Lit setter.
-    static get properties(): PropertyDeclarations {
-      return {
-        hass: {},
-      };
-    }
-
-    // Exists so all methods can safely call super method
-    protected hassConnected() {
-      // tslint:disable-next-line
-    }
-
-    protected hassReconnected() {
-      // tslint:disable-next-line
-    }
-
-    protected hassDisconnected() {
-      // tslint:disable-next-line
-    }
-
-    protected panelUrlChanged(_newPanelUrl) {
-      // tslint:disable-next-line
-    }
-
-    protected hassChanged(hass, _oldHass) {
-      this.__provideHass.forEach((el) => {
-        (el as any).hass = hass;
-      });
-    }
-
-    public provideHass(el) {
-      this.__provideHass.push(el);
-      // @ts-ignore
-      el.hass = this.hass;
-    }
-
-    protected _updateHass(obj: Partial<HomeAssistant>) {
-      // @ts-ignore
-      if (!this.hass) {
-        this._pendingHass = { ...this._pendingHass, ...obj };
-        return;
-      }
-      // @ts-ignore
-      this.hass = { ...this.hass, ...obj };
-    }
-  };
diff --git a/src/state/hass-element.ts b/src/state/hass-element.ts
index c225ef9224e6..9aaa9ccc6ac6 100644
--- a/src/state/hass-element.ts
+++ b/src/state/hass-element.ts
@@ -1,4 +1,3 @@
-import HassBaseMixin from "./hass-base-mixin";
 import AuthMixin from "./auth-mixin";
 import TranslationsMixin from "./translations-mixin";
 import ThemesMixin from "./themes-mixin";
@@ -11,12 +10,13 @@ import NotificationMixin from "./notification-mixin";
 import DisconnectToastMixin from "./disconnect-toast-mixin";
 import { hapticMixin } from "./haptic-mixin";
 import { urlSyncMixin } from "./url-sync-mixin";
-import { LitElement } from "lit-element";
+import { Constructor } from "../types";
+import { HassBaseEl } from "./hass-base-mixin";
 
-const ext = <T>(baseClass: T, mixins): T =>
+const ext = <T extends Constructor>(baseClass: T, mixins): T =>
   mixins.reduceRight((base, mixin) => mixin(base), baseClass);
 
-export class HassElement extends ext(HassBaseMixin(LitElement), [
+export class HassElement extends ext(HassBaseEl, [
   AuthMixin,
   ThemesMixin,
   TranslationsMixin,
diff --git a/src/state/more-info-mixin.ts b/src/state/more-info-mixin.ts
index 9cd8a129390c..8b3af120d505 100644
--- a/src/state/more-info-mixin.ts
+++ b/src/state/more-info-mixin.ts
@@ -1,6 +1,5 @@
-import { Constructor, LitElement } from "lit-element";
-
 import { HassBaseEl } from "./hass-base-mixin";
+import { Constructor } from "../types";
 
 declare global {
   // for fire event
@@ -11,7 +10,7 @@ declare global {
   }
 }
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     private _moreInfoEl?: any;
 
diff --git a/src/state/notification-mixin.ts b/src/state/notification-mixin.ts
index 726f335052d6..5149e3a80c0a 100644
--- a/src/state/notification-mixin.ts
+++ b/src/state/notification-mixin.ts
@@ -1,7 +1,11 @@
-export default (superClass) =>
+import { HassBaseEl } from "./hass-base-mixin";
+import { Constructor } from "../types";
+
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
+      // @ts-ignore
       this.registerDialog({
         dialogShowEvent: "hass-notification",
         dialogTag: "notification-manager",
diff --git a/src/state/sidebar-mixin.ts b/src/state/sidebar-mixin.ts
index 0432be00147e..456ec7120bd1 100644
--- a/src/state/sidebar-mixin.ts
+++ b/src/state/sidebar-mixin.ts
@@ -1,8 +1,7 @@
 import { storeState } from "../util/ha-pref-storage";
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import { HASSDomEvent } from "../common/dom/fire_event";
-import { HomeAssistant } from "../types";
+import { HomeAssistant, Constructor } from "../types";
 
 interface DockSidebarParams {
   dock: HomeAssistant["dockedSidebar"];
@@ -19,7 +18,7 @@ declare global {
   }
 }
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
diff --git a/src/state/themes-mixin.ts b/src/state/themes-mixin.ts
index b97419237ee4..4fd14c823af9 100644
--- a/src/state/themes-mixin.ts
+++ b/src/state/themes-mixin.ts
@@ -1,9 +1,9 @@
 import applyThemesOnElement from "../common/dom/apply_themes_on_element";
 import { storeState } from "../util/ha-pref-storage";
 import { subscribeThemes } from "../data/ws-themes";
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import { HASSDomEvent } from "../common/dom/fire_event";
+import { Constructor } from "../types";
 
 declare global {
   // for add event listener
@@ -12,7 +12,7 @@ declare global {
   }
 }
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
diff --git a/src/state/translations-mixin.ts b/src/state/translations-mixin.ts
index edce6341cc73..da7c3f2f3fd0 100644
--- a/src/state/translations-mixin.ts
+++ b/src/state/translations-mixin.ts
@@ -4,11 +4,10 @@ import {
   getLocalLanguage,
   getUserLanguage,
 } from "../util/hass-translation";
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import { computeLocalize } from "../common/translations/localize";
 import { computeRTL } from "../common/util/compute_rtl";
-import { HomeAssistant } from "../types";
+import { HomeAssistant, Constructor } from "../types";
 import { storeState } from "../util/ha-pref-storage";
 import {
   getHassTranslations,
@@ -19,7 +18,7 @@ import {
  * superClass needs to contain `this.hass` and `this._updateHass`.
  */
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default <T extends Constructor<HassBaseEl>>(superClass: T) =>
   class extends superClass {
     // tslint:disable-next-line: variable-name
     private __coreProgress?: string;
diff --git a/src/state/url-sync-mixin.ts b/src/state/url-sync-mixin.ts
index 920066bd8514..94325cab7bb8 100644
--- a/src/state/url-sync-mixin.ts
+++ b/src/state/url-sync-mixin.ts
@@ -1,12 +1,12 @@
-import { Constructor, LitElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import { fireEvent } from "../common/dom/fire_event";
+import { Constructor } from "../types";
 
 /* tslint:disable:no-console */
 const DEBUG = false;
 
-export const urlSyncMixin = (
-  superClass: Constructor<LitElement & HassBaseEl>
+export const urlSyncMixin = <T extends Constructor<HassBaseEl>>(
+  superClass: T
 ) =>
   // Disable this functionality in the demo.
   __DEMO__
diff --git a/src/state/zha-dialog-mixin.ts b/src/state/zha-dialog-mixin.ts
index 600c9c49723f..ba6e294c2dbd 100644
--- a/src/state/zha-dialog-mixin.ts
+++ b/src/state/zha-dialog-mixin.ts
@@ -1,10 +1,11 @@
-import { Constructor, LitElement } from "lit-element";
+import { UpdatingElement } from "lit-element";
 import { HassBaseEl } from "./hass-base-mixin";
 import {
   showZHADeviceInfoDialog,
   ZHADeviceInfoDialogParams,
 } from "../dialogs/zha-device-info-dialog/show-dialog-zha-device-info";
 import { HASSDomEvent } from "../common/dom/fire_event";
+import { Constructor } from "../types";
 
 declare global {
   // for fire event
@@ -15,7 +16,7 @@ declare global {
   }
 }
 
-export default (superClass: Constructor<LitElement & HassBaseEl>) =>
+export default (superClass: Constructor<UpdatingElement & HassBaseEl>) =>
   class extends superClass {
     protected firstUpdated(changedProps) {
       super.firstUpdated(changedProps);
diff --git a/src/types.ts b/src/types.ts
index d67d460285d7..4288597623a7 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -40,6 +40,8 @@ declare global {
   }
 }
 
+export type Constructor<T = {}> = new (...args: any[]) => T;
+
 export interface WebhookError {
   code: number;
   message: string;