diff --git a/src/extensions.json b/src/extensions.json
new file mode 100644
index 0000000..995904f
--- /dev/null
+++ b/src/extensions.json
@@ -0,0 +1,7 @@
+{
+    "image/jpeg": ".jpg",
+    "image/png": ".png",
+    "image/gif": ".gif",
+    "video/mp4": ".mp4",
+    "video/webm": ".webm"
+}
diff --git a/src/interpolate.js b/src/interpolate.js
index 70e3755..9baa6a7 100644
--- a/src/interpolate.js
+++ b/src/interpolate.js
@@ -5,12 +5,7 @@ const path = require('path');
 const url = require('url');
 const dateFns = require('date-fns');
 
-const extensions = {
-    'image/jpeg': '.jpg',
-    'image/gif': '.gif',
-    'video/mp4': '.mp4',
-    'video/webm': '.webm'
-};
+const extensions = require('./extensions.json');
 
 function interpolate(pattern, user, post, item) {
     const dateFormat = config.library.dateFormat || 'YYYYMMDD';
diff --git a/src/methods/redditImage.js b/src/methods/redditImage.js
index 791e81e..83690f4 100644
--- a/src/methods/redditImage.js
+++ b/src/methods/redditImage.js
@@ -2,8 +2,15 @@
 
 const util = require('util');
 const config = require('config');
+const path = require('path');
 const fetch = require('node-fetch');
 
+const extensions = require('../extensions.json');
+
+function reverseLookup(extension) {
+    return Object.keys(extensions).find(mime => extensions[mime] === extension);
+};
+
 function redditImage(post) {
     return Promise.resolve({
         album: null,
@@ -12,7 +19,7 @@ function redditImage(post) {
             url: post.url,
             title: post.title,
             datetime: post.datetime,
-            type: 'image/jpeg',
+            type: reverseLookup(path.extname(post.url)),
             original: post
         }]
     });