diff --git a/CHANGELOG.md b/CHANGELOG.md
index 714e9767..d3c4c31b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ CHANGELOG
   the [Device Tracking Add-on](https://dev.maxmind.com/minfraud/track-devices)
   for explicit device linking. You may provide this by providing
   `trackingToken` to `Device`.
+* Added `FatZebra` to the `Processor` enum.
 
 8.3.0 (2026-01-20)
 ------------------
diff --git a/src/constants.ts b/src/constants.ts
index 01c0b42d..9f41765b 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -98,6 +98,7 @@ export enum Processor {
   Epx = 'epx',
   Eway = 'eway',
   Exact = 'exact',
+  FatZebra = 'fat_zebra',
   FirstAtlanticCommerce = 'first_atlantic_commerce',
   FirstData = 'first_data',
   Fiserv = 'fiserv',