diff --git a/packages/accounts-2fa/2fa-server.js b/packages/accounts-2fa/2fa-server.js
index 45f701a2ee..188d829489 100644
--- a/packages/accounts-2fa/2fa-server.js
+++ b/packages/accounts-2fa/2fa-server.js
@@ -59,7 +59,7 @@ Meteor.methods({
     });
     const svg = new QRCode(uri).svg();
 
-    await Meteor.users.update(
+    await Meteor.users.updateAsync(
       { _id: user._id },
       {
         $set: {
@@ -94,7 +94,7 @@ Meteor.methods({
       Accounts._handleError('Invalid 2FA code', true, 'invalid-2fa-code');
     }
 
-    await Meteor.users.update(
+    await Meteor.users.updateAsync(
       { _id: user._id },
       {
         $set: {
@@ -113,7 +113,7 @@ Meteor.methods({
       throw new Meteor.Error(400, 'No user logged in.');
     }
 
-    await Meteor.users.update(
+    await Meteor.users.updateAsync(
       { _id: userId },
       {
         $unset: {
diff --git a/packages/accounts-password/email_tests.js b/packages/accounts-password/email_tests.js
index afcdef3905..6c78320c58 100644
--- a/packages/accounts-password/email_tests.js
+++ b/packages/accounts-password/email_tests.js
@@ -49,9 +49,9 @@ testAsyncMulti("accounts emails - reset password flow", [
     }));
   },
   function (test, expect) {
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   },
   function (test, expect) {
@@ -62,9 +62,9 @@ testAsyncMulti("accounts emails - reset password flow", [
       }));
   },
   function (test, expect) {
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   }
 ]);
@@ -168,40 +168,45 @@ testAsyncMulti("accounts emails - verify email flow", [
       {email: this.email, password: 'foobar'},
       loggedIn(test, expect));
   },
-  function (test, expect) {
-    test.equal(Meteor.user().emails.length, 1);
-    test.equal(Meteor.user().emails[0].address, this.email);
-    test.isFalse(Meteor.user().emails[0].verified);
+  async function (test, expect) {
+    const u = await Meteor.user();
+    test.equal(u.emails.length, 1);
+    test.equal(u.emails[0].address, this.email);
+    test.isFalse(u.emails[0].verified);
     // We should NOT be publishing things like verification tokens!
-    test.isFalse(Object.prototype.hasOwnProperty.call(Meteor.user(), 'services'));
+    test.isFalse(Object.prototype.hasOwnProperty.call(u, 'services'));
   },
   function (test, expect) {
     getVerifyEmailToken(this.email, test, expect);
   },
   function (test, expect) {
     // Log out, to test that verifyEmail logs us back in.
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   },
   function (test, expect) {
     Accounts.verifyEmail(verifyEmailToken,
                          loggedIn(test, expect));
   },
-  function (test, expect) {
-    test.equal(Meteor.user().emails.length, 1);
-    test.equal(Meteor.user().emails[0].address, this.email);
-    test.isTrue(Meteor.user().emails[0].verified);
+  async function (test, expect) {
+    const u = await Meteor.user();
+
+    test.equal(u.emails.length, 1);
+    test.equal(u.emails[0].address, this.email);
+    test.isTrue(u.emails[0].verified);
   },
   function (test, expect) {
     Accounts.connection.call(
       "addEmailForTestAndVerify", this.anotherEmail,
-      expect((error, result) => {
+      expect(async (error, result) => {
+        const u = await Meteor.user();
+
         test.isFalse(error);
-        test.equal(Meteor.user().emails.length, 2);
-        test.equal(Meteor.user().emails[1].address, this.anotherEmail);
-        test.isFalse(Meteor.user().emails[1].verified);
+        test.equal(u.emails.length, 2);
+        test.equal(u.emails[1].address, this.anotherEmail);
+        test.isFalse(u.emails[1].verified);
       }));
   },
   function (test, expect) {
@@ -210,9 +215,9 @@ testAsyncMulti("accounts emails - verify email flow", [
   function (test, expect) {
     // Log out, to test that verifyEmail logs us back in. (And if we don't
     // do that, waitUntilLoggedIn won't be able to prevent race conditions.)
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   },
   function (test, expect) {
@@ -226,11 +231,12 @@ testAsyncMulti("accounts emails - verify email flow", [
   function (test, expect) {
     Accounts.connection.call(
       "addEmailForTestAndVerify", this.anotherEmailCaps,
-      expect((error, result) => {
+      expect(async (error, result) => {
+        const u = await Meteor.user();
         test.isFalse(error);
-        test.equal(Meteor.user().emails.length, 3);
-        test.equal(Meteor.user().emails[2].address, this.anotherEmailCaps);
-        test.isFalse(Meteor.user().emails[2].verified);
+        test.equal(u.emails.length, 3);
+        test.equal(u.emails[2].address, this.anotherEmailCaps);
+        test.isFalse(u.emails[2].verified);
       }));
   },
   function (test, expect) {
@@ -239,23 +245,25 @@ testAsyncMulti("accounts emails - verify email flow", [
   function (test, expect) {
     // Log out, to test that verifyEmail logs us back in. (And if we don't
     // do that, waitUntilLoggedIn won't be able to prevent race conditions.)
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   },
   function (test, expect) {
     Accounts.verifyEmail(verifyEmailToken,
                          loggedIn(test, expect));
   },
-  function (test, expect) {
-    test.equal(Meteor.user().emails[2].address, this.anotherEmailCaps);
-    test.isTrue(Meteor.user().emails[2].verified);
+  async function (test, expect) {
+    const u = await Meteor.user();
+
+    test.equal(u.emails[2].address, this.anotherEmailCaps);
+    test.isTrue(u.emails[2].verified);
   },
   function (test, expect) {
-    Meteor.logout(expect((error) => {
+    Meteor.logout(expect(async (error) => {
       test.equal(error, undefined);
-      test.equal(Meteor.user(), null);
+      test.equal(await Meteor.user(), null);
     }));
   }
 ]);
diff --git a/packages/accounts-password/email_tests_setup.js b/packages/accounts-password/email_tests_setup.js
index e06fbfa789..fe393fb663 100644
--- a/packages/accounts-password/email_tests_setup.js
+++ b/packages/accounts-password/email_tests_setup.js
@@ -44,7 +44,7 @@ Meteor.methods(
     addEmailForTestAndVerify:
       async email => {
         check(email, String);
-        await Meteor.users.update(
+        await Meteor.users.updateAsync(
           { _id: Accounts.userId() },
           { $push: { emails: { address: email, verified: false } } });
         await Accounts.sendVerificationEmail(Accounts.userId(), email);
diff --git a/packages/accounts-password/password_tests.js b/packages/accounts-password/password_tests.js
index 5cf096a9da..6d80c80552 100644
--- a/packages/accounts-password/password_tests.js
+++ b/packages/accounts-password/password_tests.js
@@ -700,8 +700,8 @@ if (Meteor.isClient) (() => {
     // test Meteor.user(). This test properly belongs in
     // accounts-base/accounts_tests.js, but this is where the tests that
     // actually log in are.
-    function (test, expect) {
-      const clientUser = Meteor.user();
+    async function (test, expect) {
+      const clientUser = await Meteor.user();
       Accounts.connection.call('testMeteorUser', expect((err, result) => {
         test.equal(result._id, clientUser._id);
         test.equal(result.username, clientUser.username);
diff --git a/packages/accounts-password/password_tests_setup.js b/packages/accounts-password/password_tests_setup.js
index 80964c72fd..48a34c8766 100644
--- a/packages/accounts-password/password_tests_setup.js
+++ b/packages/accounts-password/password_tests_setup.js
@@ -128,7 +128,7 @@ Meteor.methods(
         if (!this.userId) throw new Error("Not logged in!");
         await Meteor
           .users
-          .update(this.userId, { $unset: { profile: 1, username: 1 } });
+          .updateAsync(this.userId, { $unset: { profile: 1, username: 1 } });
       },
 
     expireTokens:
@@ -137,6 +137,6 @@ Meteor.methods(
       },
 
     removeUser:
-      async username => await Meteor.users.remove({ "username": username }),
+      async username => await Meteor.users.removeAsync({ "username": username }),
   }
 );
diff --git a/packages/minimongo/constants.js b/packages/minimongo/constants.js
index fc4c5b9225..3795a8dc68 100644
--- a/packages/minimongo/constants.js
+++ b/packages/minimongo/constants.js
@@ -18,3 +18,5 @@ export const ASYNC_COLLECTION_METHODS = [
 ];
 
 export const ASYNC_CURSOR_METHODS = ['count', 'fetch', 'forEach', 'map'];
+
+export const CLIENT_ONLY_METHODS = ["findOne", "insert", "remove", "update", "upsert"];
diff --git a/packages/mongo/collection.js b/packages/mongo/collection.js
index 73d8590563..6d2199965c 100644
--- a/packages/mongo/collection.js
+++ b/packages/mongo/collection.js
@@ -959,7 +959,7 @@ Object.assign(Mongo.Collection.prototype, {
       // If the user provided a callback and the collection implements this
       // operation asynchronously, then queryRet will be undefined, and the
       // result will be returned through the callback instead.
-      return this._collection.updateAsync(
+      return this._collection.update(
         selector,
         modifier,
         options,
@@ -1258,18 +1258,3 @@ function popCallbackFromArgs(args) {
   }
 }
 
-
-// XXX: IN Meteor 3.x this code was not working....
-// It throws an error when trying to call a method on the collection.
-// the error normally is:
-// TypeError: this[methodName] is not a function
-// ASYNC_COLLECTION_METHODS.forEach(methodName => {
-//   const methodNameAsync = getAsyncMethodName(methodName);
-//   Mongo.Collection.prototype[methodNameAsync] = function(...args) {
-//     try {
-//       return Promise.resolve(this[methodName](...args));
-//     } catch (error) {
-//       return Promise.reject(error);
-//     }
-//   };
-// });
diff --git a/packages/mongo/mongo_driver.js b/packages/mongo/mongo_driver.js
index 0c2e021036..8fc3644b86 100644
--- a/packages/mongo/mongo_driver.js
+++ b/packages/mongo/mongo_driver.js
@@ -17,6 +17,7 @@ var MongoDB = NpmModuleMongodb;
 import { DocFetcher } from "./doc_fetcher.js";
 import {
   ASYNC_CURSOR_METHODS,
+  CLIENT_ONLY_METHODS,
   getAsyncMethodName
 } from "meteor/minimongo/constants";
 import { Meteor } from "meteor/meteor";
@@ -359,6 +360,7 @@ MongoConnection.prototype.insertAsync = async function (collection_name, documen
   });
 };
 
+
 // Cause queries that may be affected by the selector to poll in this write
 // fence.
 MongoConnection.prototype._refresh = async function (collectionName, selector) {
@@ -791,6 +793,17 @@ MongoConnection.prototype.dropIndexAsync = async function (collectionName, index
   var indexName =  await collection.dropIndex(index);
 };
 
+
+CLIENT_ONLY_METHODS.forEach(function (m) {
+  MongoConnection.prototype[m] = function () {
+    throw new Error(
+      `${m} +  is not available on the server. Please use ${getAsyncMethodName(
+        m
+      )}() instead.`
+    );
+  };
+});
+
 // CURSORS
 
 // There are several classes which relate to cursors:
@@ -868,6 +881,12 @@ Cursor.prototype.countAsync = async function () {
   );
 };
 
+Cursor.prototype.count = function () {
+  throw new Error(
+    "count() is not avaible on the server. Please use countAsync() instead."
+  );
+};
+
 [...ASYNC_CURSOR_METHODS, Symbol.iterator, Symbol.asyncIterator].forEach(methodName => {
   // count is handled specially since we don't want to create a cursor.
   // it is still included in ASYNC_CURSOR_METHODS because we still want an async version of it to exist.
diff --git a/packages/mongo/remote_collection_driver.js b/packages/mongo/remote_collection_driver.js
index c3954a9cf9..36a8a30910 100644
--- a/packages/mongo/remote_collection_driver.js
+++ b/packages/mongo/remote_collection_driver.js
@@ -1,6 +1,7 @@
 import {
   ASYNC_COLLECTION_METHODS,
-  getAsyncMethodName
+  getAsyncMethodName,
+  CLIENT_ONLY_METHODS
 } from "meteor/minimongo/constants";
 
 MongoInternals.RemoteCollectionDriver = function (
@@ -30,22 +31,33 @@ Object.assign(MongoInternals.RemoteCollectionDriver.prototype, {
   open: function (name) {
     var self = this;
     var ret = {};
-    REMOTE_COLLECTION_METHODS.forEach(
-      function (m) {
-        ret[m] = _.bind(self.mongo[m], self.mongo, name);
+    REMOTE_COLLECTION_METHODS.forEach(function (m) {
+      ret[m] = _.bind(self.mongo[m], self.mongo, name);
 
-        if (!ASYNC_COLLECTION_METHODS.includes(m)) return;
-        const asyncMethodName = getAsyncMethodName(m);
-        ret[asyncMethodName] = function (...args) {
-          try {
-            return Promise.resolve(ret[m](...args));
-          } catch (error) {
-            return Promise.reject(error);
-          }
+      if (!ASYNC_COLLECTION_METHODS.includes(m)) return;
+      const asyncMethodName = getAsyncMethodName(m);
+      ret[asyncMethodName] = function (...args) {
+        try {
+          return Promise.resolve(ret[m](...args));
+        } catch (error) {
+          return Promise.reject(error);
         }
-      });
+      };
+    });
+
+    CLIENT_ONLY_METHODS.forEach(function (m) {
+      ret[m] = _.bind(self.mongo[m], self.mongo, name);
+
+      ret[m] = function (...args) {
+        throw new Error(
+          `${m} +  is not available on the server. Please use ${getAsyncMethodName(
+            m
+          )}() instead.`
+        );
+      };
+    });
     return ret;
-  }
+  },
 });
 
 // Create the singleton RemoteCollectionDriver only on demand, so we