diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
index 18eee65..8a0bf78 100644
--- a/.github/pull_request_template.md
+++ b/.github/pull_request_template.md
@@ -1,6 +1,7 @@
 Feel free to open a PR before all of these items have been completed.
 
 Pull Request Checklist
+ - [ ] Pull request has been made against `dev` branch.
  - [ ] Pull request includes a description of the change and the reason behind it.
  - [ ] Pull request [uses keywords](https://help.github.com/en/articles/closing-issues-using-keywords) to close relevant [issues](https://github.com/uptake/autofocus/issues).
  - [ ] Pull request includes unit tests for any new functionality.
@@ -11,4 +12,4 @@ Maintainer's responsibilities:
 - [ ] `_version.py` has been updated.
 - [ ] `CHANGELOG.md` has been updated.
 - [ ] Updated app container has been pushed, if relevant, with current version number.
-- [ ] App container version number has been updated in README.
+- [ ] App container version number has been updated everywhere in README.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 30f2432..5e523b7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
+# [1.2.4] - 2019-10-13
+### Changed
+ - Service gets image file extensions from `mimetypes` instead of using a hard-coded list.
+
 # [1.2.3] - 2019-8-22
 ### Changed
  - Tests and instructions now refer to "localhost" instead of "0.0.0.0".
diff --git a/autofocus/_version.py b/autofocus/_version.py
index bc86c94..b3f9ac7 100644
--- a/autofocus/_version.py
+++ b/autofocus/_version.py
@@ -1 +1 @@
-__version__ = "1.2.2"
+__version__ = "1.2.4"
diff --git a/autofocus/predict/app/requests/Validator.py b/autofocus/predict/app/requests/Validator.py
index 0381246..6247ae5 100644
--- a/autofocus/predict/app/requests/Validator.py
+++ b/autofocus/predict/app/requests/Validator.py
@@ -1,11 +1,14 @@
+import mimetypes
 from abc import ABC, abstractmethod
 
 from flask import abort, jsonify, make_response
 from flask_api import status
 
 
-ALLOWED_IMAGE_FILES = set(["png", "jpg", "jpeg", "gif", "bmp"])
-ALLOWED_ZIP_FILES = {"zip"}
+ALLOWED_IMAGE_FILES = set(
+    k for k, v in mimetypes.types_map.items() if v.startswith("image/")
+)
+ALLOWED_ZIP_FILES = {".zip"}
 
 
 class Validator(ABC):
diff --git a/autofocus/predict/app/utils.py b/autofocus/predict/app/utils.py
index 3d21c53..14d4b48 100644
--- a/autofocus/predict/app/utils.py
+++ b/autofocus/predict/app/utils.py
@@ -11,4 +11,4 @@ def allowed_file(filename, allowed_extensions):
         bool: whether the filename is in allowed extensions
 
     """
-    return Path(filename).suffix.lower().replace(".", "") in allowed_extensions
+    return Path(filename).suffix.lower() in allowed_extensions
diff --git a/setup.py b/setup.py
index 985abda..4dd63dc 100644
--- a/setup.py
+++ b/setup.py
@@ -31,6 +31,6 @@
     extras_require={"dev": regular_packages + dev_packages},
     author="Greg Gandenberger",
     author_email="gsganden@gmail.com",
-    url="https://github.com/UptakeOpenSource/autofocus",
+    url="https://github.com/uptake/autofocus",
     long_description_content_type="text/markdown",
 )