diff --git a/src/config.js b/src/config.js
index 856a514..4d7cd86 100644
--- a/src/config.js
+++ b/src/config.js
@@ -69,6 +69,7 @@ const defaultConfig = {
   "accountAgeDeniedMessage": "Your Discord account is not old enough to contact modmail.",
 
   "relaySmallAttachmentsAsAttachments": false,
+  "smallAttachmentLimit": 1024 * 1024 * 2,
 
   "port": 8890,
   "url": null,
@@ -117,6 +118,11 @@ for (const opt of required) {
   }
 }
 
+if (finalConfig.smallAttachmentLimit > 1024 * 1024 * 8) {
+  finalConfig.smallAttachmentLimit = 1024 * 1024 * 8;
+  console.log('[WARN] smallAttachmentLimit capped at 8MB');
+}
+
 // Make sure mainGuildId is internally always an array
 if (! Array.isArray(finalConfig['mainGuildId'])) {
   finalConfig['mainGuildId'] = [finalConfig['mainGuildId']];