diff --git a/.env.sample b/.env.sample
index b0c38a84..37b626a5 100644
--- a/.env.sample
+++ b/.env.sample
@@ -94,6 +94,10 @@ FORCE_HTTPS=true
 # the maintainers
 ENABLE_UPDATES=true
 
+# Override the maxium size of document imports, could be required if you have
+# especially large Word documents with embedded imagery
+MAXIMUM_IMPORT_SIZE=5120000
+
 # You may enable or disable debugging categories to increase the noisiness of
 # logs. The default is a good balance
 DEBUG=cache,presenters,events,emails,mailer,utils,multiplayer,server,services
diff --git a/app/stores/DocumentsStore.js b/app/stores/DocumentsStore.js
index ebb0ad63..ae949211 100644
--- a/app/stores/DocumentsStore.js
+++ b/app/stores/DocumentsStore.js
@@ -8,6 +8,7 @@ import naturalSort from "shared/utils/naturalSort";
 import BaseStore from "stores/BaseStore";
 import RootStore from "stores/RootStore";
 import Document from "models/Document";
+import env from "env";
 import type { FetchOptions, PaginationParams, SearchResult } from "types";
 import { client } from "utils/ApiClient";
 
@@ -28,6 +29,7 @@ export default class DocumentsStore extends BaseStore<Document> {
     "text/html",
     "application/msword",
     "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+    "application/octet-stream",
   ];
 
   constructor(rootStore: RootStore) {
@@ -529,6 +531,14 @@ export default class DocumentsStore extends BaseStore<Document> {
     collectionId: string,
     options: ImportOptions
   ) => {
+    // file.type can be an empty string sometimes
+    if (file.type && !this.importFileTypes.includes(file.type)) {
+      throw new Error(`The selected file type is not supported (${file.type})`);
+    }
+    if (file.size > env.MAXIMUM_IMPORT_SIZE) {
+      throw new Error("The selected file was too large to import");
+    }
+
     const title = file.name.replace(/\.[^/.]+$/, "");
     const formData = new FormData();
 
diff --git a/server/api/documents.js b/server/api/documents.js
index 359420b8..232ddd56 100644
--- a/server/api/documents.js
+++ b/server/api/documents.js
@@ -5,6 +5,7 @@ import { subtractDate } from "../../shared/utils/date";
 import documentCreator from "../commands/documentCreator";
 import documentImporter from "../commands/documentImporter";
 import documentMover from "../commands/documentMover";
+import env from "../env";
 import {
   NotFoundError,
   InvalidRequestError,
@@ -1179,6 +1180,10 @@ router.post("documents.import", auth(), async (ctx) => {
   const file: any = Object.values(ctx.request.files)[0];
   ctx.assertPresent(file, "file is required");
 
+  if (file.size > env.MAXIMUM_IMPORT_SIZE) {
+    throw new InvalidRequestError("The selected file was too large to import");
+  }
+
   ctx.assertUuid(collectionId, "collectionId must be an uuid");
   if (parentDocumentId) {
     ctx.assertUuid(parentDocumentId, "parentDocumentId must be an uuid");
diff --git a/server/commands/documentImporter.js b/server/commands/documentImporter.js
index da7d1c65..87b8a8cd 100644
--- a/server/commands/documentImporter.js
+++ b/server/commands/documentImporter.js
@@ -44,6 +44,10 @@ const importMapping: ImportableFile[] = [
     type: "application/msword",
     getMarkdown: confluenceToMarkdown,
   },
+  {
+    type: "application/octet-stream",
+    getMarkdown: docxToMarkdown,
+  },
   {
     type:
       "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
@@ -142,6 +146,12 @@ export default async function documentImporter({
 }): Promise<{ text: string, title: string }> {
   const fileInfo = importMapping.filter((item) => {
     if (item.type === file.type) {
+      if (
+        file.type === "application/octet-stream" &&
+        path.extname(file.name) !== ".docx"
+      ) {
+        return false;
+      }
       return true;
     }
     if (item.type === "text/markdown" && path.extname(file.name) === ".md") {
diff --git a/server/commands/documentImporter.test.js b/server/commands/documentImporter.test.js
index 2324c30d..fca2ecbd 100644
--- a/server/commands/documentImporter.test.js
+++ b/server/commands/documentImporter.test.js
@@ -37,6 +37,75 @@ describe("documentImporter", () => {
     expect(response.title).toEqual("images");
   });
 
+  it("should convert Word Document to markdown for application/octet-stream mimetype", async () => {
+    const user = await buildUser();
+    const name = "images.docx";
+    const file = new File({
+      name,
+      type: "application/octet-stream",
+      path: path.resolve(__dirname, "..", "test", "fixtures", name),
+    });
+
+    const response = await documentImporter({
+      user,
+      file,
+      ip,
+    });
+
+    const attachments = await Attachment.count();
+    expect(attachments).toEqual(1);
+
+    expect(response.text).toContain("This is a test document for images");
+    expect(response.text).toContain("![](/api/attachments.redirect?id=");
+    expect(response.title).toEqual("images");
+  });
+
+  it("should error when a file with application/octet-stream mimetype doesn't have .docx extension", async () => {
+    const user = await buildUser();
+    const name = "normal.docx.txt";
+    const file = new File({
+      name,
+      type: "application/octet-stream",
+      path: path.resolve(__dirname, "..", "test", "fixtures", name),
+    });
+
+    let error;
+    try {
+      await documentImporter({
+        user,
+        file,
+        ip,
+      });
+    } catch (err) {
+      error = err.message;
+    }
+
+    expect(error).toEqual("File type application/octet-stream not supported");
+  });
+
+  it("should convert Word Document on Windows to markdown", async () => {
+    const user = await buildUser();
+    const name = "images.docx";
+    const file = new File({
+      name,
+      type: "application/octet-stream",
+      path: path.resolve(__dirname, "..", "test", "fixtures", name),
+    });
+
+    const response = await documentImporter({
+      user,
+      file,
+      ip,
+    });
+
+    const attachments = await Attachment.count();
+    expect(attachments).toEqual(1);
+
+    expect(response.text).toContain("This is a test document for images");
+    expect(response.text).toContain("![](/api/attachments.redirect?id=");
+    expect(response.title).toEqual("images");
+  });
+
   it("should convert HTML Document to markdown", async () => {
     const user = await buildUser();
     const name = "webpage.html";
@@ -118,7 +187,7 @@ describe("documentImporter", () => {
     const name = "markdown.md";
     const file = new File({
       name,
-      type: "application/octet-stream",
+      type: "application/lol",
       path: path.resolve(__dirname, "..", "test", "fixtures", name),
     });
 
diff --git a/server/env.js b/server/env.js
index 76621e57..204f6cc9 100644
--- a/server/env.js
+++ b/server/env.js
@@ -11,6 +11,7 @@ export default {
   TEAM_LOGO: process.env.TEAM_LOGO,
   SLACK_KEY: process.env.SLACK_KEY,
   SLACK_APP_ID: process.env.SLACK_APP_ID,
+  MAXIMUM_IMPORT_SIZE: process.env.MAXIMUM_IMPORT_SIZE || 1024 * 1000 * 5,
   SUBDOMAINS_ENABLED: process.env.SUBDOMAINS_ENABLED === "true",
   GOOGLE_ANALYTICS_ID: process.env.GOOGLE_ANALYTICS_ID,
   RELEASE: process.env.SOURCE_COMMIT || process.env.SOURCE_VERSION || undefined,
diff --git a/server/test/fixtures/normal.docx.txt b/server/test/fixtures/normal.docx.txt
new file mode 100644
index 00000000..2f297a1c
Binary files /dev/null and b/server/test/fixtures/normal.docx.txt differ