diff --git a/package.json b/package.json
index d0fd322..3e77667 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "firestore-mobx",
-  "version": "2.0.0-13",
+  "version": "2.0.0-14",
   "description": "Observable Firestore documents and collections using MobX",
   "main": "dist/index.js",
   "module": "dist/index.es.js",
diff --git a/src/__test/document.test.ts b/src/__test/document.test.ts
index 4045144..4a76422 100644
--- a/src/__test/document.test.ts
+++ b/src/__test/document.test.ts
@@ -1,4 +1,4 @@
-import { autorun, configure } from "mobx";
+import { autorun, configure, toJS } from "mobx";
 import { ObservableDocument } from "../document";
 import { first } from "../utils";
 import {
@@ -41,7 +41,8 @@ describe("Document", () => {
     expect(document.id).toBe("__no_id");
     expect(document.isLoading).toBe(false);
     expect(document.hasData).toBe(false);
-    expect(document.data).toBe(undefined);
+    expect(() => document.data).toThrow();
+    expect(() => document.document).toThrow();
   });
 
   it("Can observe a document by ref", async () => {
@@ -54,7 +55,6 @@ describe("Document", () => {
 
     expect(document.isLoading).toBe(true);
     expect(document.hasData).toBe(false);
-    expect(document.data).toBeUndefined();
 
     await document.ready().then((doc) => console.log(doc));
 
@@ -78,7 +78,6 @@ describe("Document", () => {
 
     expect(document.isLoading).toBe(true);
     expect(document.hasData).toBe(false);
-    expect(document.data).toBeUndefined();
 
     const disposeListeners = autorun(() => {
       console.log("isLoading", document.isLoading);
@@ -106,7 +105,6 @@ describe("Document", () => {
 
     expect(document.isLoading).toBe(false);
     expect(document.hasData).toBe(false);
-    expect(document.data).toBeUndefined();
 
     document.attachTo(first(snapshot.docs)?.id);
 
@@ -132,9 +130,6 @@ describe("Document", () => {
 
     expect(document.isLoading).toBe(false);
     expect(document.hasData).toBe(false);
-    expect(document.data).toBeUndefined();
-
-    // consoleInspect('snapshot', snapshot.docs.map(doc => doc.data))
 
     document.attachTo(first(snapshot.docs)?.id);
 
@@ -154,7 +149,6 @@ describe("Document", () => {
 
     const data = await document.ready();
 
-    // consoleInspect('data', doc?.data)
     expect(data).toEqual(first(collectionData));
 
     disposeListeners();
diff --git a/src/collection.ts b/src/collection.ts
index db8a364..646cc8b 100644
--- a/src/collection.ts
+++ b/src/collection.ts
@@ -59,7 +59,7 @@ export class ObservableCollection<T> {
    * if the current listeners belong to that combination or we need to update
    * them
    */
-  public constructor(
+  constructor(
     /**
      * Ref is optional because for sub-collections you might not know the full
      * path in advance. Pass undefined if you want to supply the other
@@ -75,6 +75,11 @@ export class ObservableCollection<T> {
       isEmpty: computed,
       hasDocuments: computed,
       attachTo: action,
+      /**
+       * attachTo being an action doesn't seem to be sufficient to prevent
+       * strict mode errors
+       */
+      _changeSource: action,
     });
 
     this.initializeReadyPromise();
@@ -109,11 +114,11 @@ export class ObservableCollection<T> {
     }
   }
 
-  public get isEmpty(): boolean {
+  get isEmpty(): boolean {
     return this.documents.length === 0;
   }
 
-  public get hasDocuments(): boolean {
+  get hasDocuments(): boolean {
     return this.documents.length > 0;
   }
 
@@ -121,23 +126,23 @@ export class ObservableCollection<T> {
     return this.observedCount > 0;
   }
 
-  public get path(): string | undefined {
+  get path(): string | undefined {
     return this.collectionRef ? this.collectionRef.path : undefined;
   }
 
-  public get ref(): FirebaseFirestore.CollectionReference | undefined {
+  get ref(): FirebaseFirestore.CollectionReference | undefined {
     return this.collectionRef;
   }
 
-  public attachTo(newRef: FirebaseFirestore.CollectionReference | undefined) {
-    this.changeSource(newRef);
+  attachTo(newRef: FirebaseFirestore.CollectionReference | undefined) {
+    this._changeSource(newRef);
     /**
      * Return this so we can chain ready()
      */
     return this;
   }
 
-  private changeSource(newRef?: FirebaseFirestore.CollectionReference) {
+  _changeSource(newRef?: FirebaseFirestore.CollectionReference) {
     if (!this.collectionRef && !newRef) {
       // this.logDebug("Ignore change source");
       return;
@@ -178,7 +183,7 @@ export class ObservableCollection<T> {
     }
   }
 
-  public async add(data: T) {
+  async add(data: T) {
     if (!hasReference(this.collectionRef)) {
       this.handleError(
         new Error(`Can not add a document to a collection that has no ref`),
@@ -191,7 +196,7 @@ export class ObservableCollection<T> {
     return this.collectionRef.add(data);
   }
 
-  public ready() {
+  ready() {
     const isListening = !!this.onSnapshotUnsubscribeFn;
 
     if (!isListening) {
@@ -342,7 +347,7 @@ export class ObservableCollection<T> {
     });
   }
 
-  public set query(queryCreatorFn: QueryCreatorFn | undefined) {
+  set query(queryCreatorFn: QueryCreatorFn | undefined) {
     this.logDebug("Set query");
 
     this.queryCreatorFn = queryCreatorFn;
diff --git a/src/document.ts b/src/document.ts
index b0e6f49..1a24b63 100644
--- a/src/document.ts
+++ b/src/document.ts
@@ -1,12 +1,12 @@
 import {
   action,
   computed,
-  makeAutoObservable,
   makeObservable,
   observable,
   onBecomeObserved,
   onBecomeUnobserved,
   runInAction,
+  toJS,
 } from "mobx";
 import { assert, createUniqueId } from "./utils";
 
@@ -20,14 +20,14 @@ export interface Document<T> {
   ref: FirebaseFirestore.DocumentReference;
 }
 
-function isDocumentReference<T>(
-  source: SourceType<T>,
+function isDocumentReference(
+  source: SourceType,
 ): source is FirebaseFirestore.DocumentReference {
   return (source as FirebaseFirestore.DocumentReference).set !== undefined;
 }
 
-function isCollectionReference<T>(
-  source: SourceType<T>,
+function isCollectionReference(
+  source: SourceType,
 ): source is FirebaseFirestore.CollectionReference {
   return (source as FirebaseFirestore.CollectionReference).doc !== undefined;
 }
@@ -40,10 +40,9 @@ function getPathFromCollectionRef(
 
 const NO_DATA = "__no_data" as const;
 
-type SourceType<T> =
+type SourceType =
   | FirebaseFirestore.DocumentReference
-  | FirebaseFirestore.CollectionReference
-  | Document<T>;
+  | FirebaseFirestore.CollectionReference;
 
 export class ObservableDocument<T> {
   _data: T | typeof NO_DATA = NO_DATA;
@@ -64,7 +63,7 @@ export class ObservableDocument<T> {
 
   onError?: (err: Error) => void;
 
-  public constructor(source?: SourceType<T>, options?: Options) {
+  constructor(source?: SourceType, options?: Options) {
     makeObservable(this, {
       _data: observable,
       isLoading: observable,
@@ -72,6 +71,11 @@ export class ObservableDocument<T> {
       document: computed,
       attachTo: action,
       hasData: computed,
+      /**
+       * attachTo being an action doesn't seem to be sufficient to prevent
+       * strict mode errors.
+       */
+      _changeLoadingState: action,
     });
 
     if (options) {
@@ -97,20 +101,7 @@ export class ObservableDocument<T> {
        * In this case we have data to wait on from the start. So initialize the
        * promise and resolve function.
        */
-      this.changeLoadingState(true);
-    } else {
-      assert(source.ref, "Missing ref in source");
-      /**
-       * Source is type Document<T>, typically passed in from the docs  data of
-       * an ObservableCollection instance.
-       */
-      this.documentRef = source.ref;
-      // not sure why ref can be undefined here. Maybe a bug in gemini
-      this.collectionRef = source.ref?.parent;
-      this.sourcePath = source.ref?.path;
-      this.logDebug("Constructor from Document<T>");
-
-      this._data = source.data;
+      this._changeLoadingState(true);
     }
 
     onBecomeObserved(this, "_data", () => this.resumeUpdates());
@@ -120,13 +111,11 @@ export class ObservableDocument<T> {
     onBecomeUnobserved(this, "isLoading", () => this.suspendUpdates());
   }
 
-  public get id(): string {
+  get id(): string {
     return this.documentRef ? this.documentRef.id : "__no_id";
   }
 
-  public attachTo(
-    documentIdOrRef?: string | FirebaseFirestore.DocumentReference,
-  ) {
+  attachTo(documentIdOrRef?: string | FirebaseFirestore.DocumentReference) {
     if (!documentIdOrRef || typeof documentIdOrRef === "string") {
       this.changeSourceViaId(documentIdOrRef);
     } else {
@@ -139,14 +128,15 @@ export class ObservableDocument<T> {
     return this;
   }
 
-  public get data(): T | undefined {
-    if (!this.documentRef || this._data === NO_DATA) return;
+  get data(): T /* | undefined */ {
+    assert(this.documentRef && this._data !== NO_DATA, "No data available");
+    // if (!this.documentRef || this._data === NO_DATA) return;
 
-    return this._data;
+    return toJS(this._data);
   }
 
-  public get document(): Document<T> | undefined {
-    if (!this.documentRef || this._data === NO_DATA) return;
+  get document(): Document<T> {
+    assert(this.documentRef && this._data !== NO_DATA, "No document available");
 
     /**
      * For document we return the data as non-observable by converting it to a
@@ -155,7 +145,7 @@ export class ObservableDocument<T> {
      */
     return {
       id: this.documentRef.id,
-      data: this._data,
+      data: this.data,
       ref: this.documentRef,
     };
   }
@@ -164,19 +154,16 @@ export class ObservableDocument<T> {
     return this.observedCount > 0;
   }
 
-  public get ref(): FirebaseFirestore.DocumentReference | undefined {
+  get ref(): FirebaseFirestore.DocumentReference {
+    assert(this.documentRef, "No document ref available");
     return this.documentRef;
   }
 
-  public set ref(newRef: FirebaseFirestore.DocumentReference | undefined) {
-    this.changeSourceViaRef(newRef);
-  }
-
-  public get path(): string | undefined {
+  get path(): string | undefined {
     return this.documentRef ? this.documentRef.path : undefined;
   }
 
-  public async update(
+  async update(
     fields: FirebaseFirestore.UpdateData,
     precondition?: FirebaseFirestore.Precondition,
   ) {
@@ -186,21 +173,21 @@ export class ObservableDocument<T> {
     return this.documentRef.update(fields, precondition);
   }
 
-  public async set(data: Partial<T>, options?: FirebaseFirestore.SetOptions) {
+  async set(data: Partial<T>, options?: FirebaseFirestore.SetOptions) {
     if (!this.documentRef) {
       throw Error("Can not set data on document with undefined ref");
     }
     return this.documentRef.set(data, options || {});
   }
 
-  public delete() {
+  delete() {
     if (!this.documentRef) {
       throw Error("Can not delete document with undefined ref");
     }
     return this.documentRef.delete();
   }
 
-  public ready(): Promise<T | undefined> {
+  ready(): Promise<T | undefined> {
     const isListening = !!this.onSnapshotUnsubscribeFn;
 
     if (!isListening && this.documentRef) {
@@ -220,7 +207,7 @@ export class ObservableDocument<T> {
     return this.readyPromise;
   }
 
-  public get hasData(): boolean {
+  get hasData(): boolean {
     return this._data !== NO_DATA;
   }
 
@@ -233,14 +220,14 @@ export class ObservableDocument<T> {
 
       this.logDebug("Call ready resolve");
 
-      readyResolve(this.data);
+      readyResolve(this.hasData ? this.data : undefined);
 
       /**
        * After the first promise has been resolved we want subsequent calls to
        * ready() to immediately return with the available data. Ready is only
        * meant to be used for initial data fetching
        */
-      this.readyPromise = Promise.resolve(this.data);
+      this.readyPromise = Promise.resolve(this.hasData ? this.data : undefined);
     }
   }
 
@@ -299,7 +286,7 @@ export class ObservableDocument<T> {
     runInAction(() => {
       this._data = snapshot.exists ? (snapshot.data() as T) : NO_DATA;
 
-      this.changeLoadingState(false);
+      this._changeLoadingState(false);
     });
   }
 
@@ -340,14 +327,14 @@ export class ObservableDocument<T> {
       }
 
       this._data = NO_DATA;
-      this.changeLoadingState(false);
+      this._changeLoadingState(false);
     } else {
       if (this.isObserved) {
         this.logDebug("Change document -> update listeners");
         this.updateListeners(true);
       }
 
-      this.changeLoadingState(true);
+      this._changeLoadingState(true);
     }
   }
 
@@ -391,14 +378,14 @@ export class ObservableDocument<T> {
       }
 
       this._data = NO_DATA;
-      this.changeLoadingState(false);
+      this._changeLoadingState(false);
     } else {
       if (this.isObserved) {
         this.logDebug("Change document -> update listeners");
         this.updateListeners(true);
       }
 
-      this.changeLoadingState(true);
+      this._changeLoadingState(true);
     }
   }
 
@@ -452,7 +439,7 @@ export class ObservableDocument<T> {
     }
   }
 
-  private changeLoadingState(isLoading: boolean) {
+  _changeLoadingState(isLoading: boolean) {
     this.logDebug(`Change loading state: ${isLoading}`);
     this.changeReady(!isLoading);
     this.isLoading = isLoading;