diff --git a/src/controllers/api/claimLibraryDailyTaskRewardController.ts b/src/controllers/api/claimLibraryDailyTaskRewardController.ts
index 6d8e1d41..3d582e46 100644
--- a/src/controllers/api/claimLibraryDailyTaskRewardController.ts
+++ b/src/controllers/api/claimLibraryDailyTaskRewardController.ts
@@ -1,4 +1,4 @@
-import { getInventory } from "@/src/services/inventoryService";
+import { addFusionPoints, getInventory } from "@/src/services/inventoryService";
 import { getAccountIdForRequest } from "@/src/services/loginService";
 import { RequestHandler } from "express";
 
@@ -17,7 +17,7 @@ export const claimLibraryDailyTaskRewardController: RequestHandler = async (req,
     }
     syndicate.Standing += rewardStanding;
 
-    inventory.FusionPoints += 80 * rewardQuantity;
+    addFusionPoints(inventory, 80 * rewardQuantity);
     await inventory.save();
 
     res.json({
diff --git a/src/controllers/api/contributeGuildClassController.ts b/src/controllers/api/contributeGuildClassController.ts
index c4fa7280..865eb868 100644
--- a/src/controllers/api/contributeGuildClassController.ts
+++ b/src/controllers/api/contributeGuildClassController.ts
@@ -2,7 +2,7 @@ import { toMongoDate } from "@/src/helpers/inventoryHelpers";
 import { getJSONfromString } from "@/src/helpers/stringHelpers";
 import { Guild } from "@/src/models/guildModel";
 import { checkClanAscensionHasRequiredContributors } from "@/src/services/guildService";
-import { getInventory } from "@/src/services/inventoryService";
+import { addFusionPoints, getInventory } from "@/src/services/inventoryService";
 import { getAccountIdForRequest } from "@/src/services/loginService";
 import { RequestHandler } from "express";
 import { Types } from "mongoose";
@@ -36,7 +36,7 @@ export const contributeGuildClassController: RequestHandler = async (req, res) =
 
     // Either way, endo is given to the contributor.
     const inventory = await getInventory(accountId, "FusionPoints");
-    inventory.FusionPoints += guild.CeremonyEndo!;
+    addFusionPoints(inventory, guild.CeremonyEndo!);
     await inventory.save();
 
     res.json({
diff --git a/src/controllers/api/sellController.ts b/src/controllers/api/sellController.ts
index 138cd3b4..4a2025c1 100644
--- a/src/controllers/api/sellController.ts
+++ b/src/controllers/api/sellController.ts
@@ -8,7 +8,8 @@ import {
     addConsumables,
     freeUpSlot,
     combineInventoryChanges,
-    addCrewShipRawSalvage
+    addCrewShipRawSalvage,
+    addFusionPoints
 } from "@/src/services/inventoryService";
 import { InventorySlot } from "@/src/types/inventoryTypes/inventoryTypes";
 import { ExportDojoRecipes } from "warframe-public-export-plus";
@@ -69,7 +70,7 @@ export const sellController: RequestHandler = async (req, res) => {
     if (payload.SellCurrency == "SC_RegularCredits") {
         inventory.RegularCredits += payload.SellPrice;
     } else if (payload.SellCurrency == "SC_FusionPoints") {
-        inventory.FusionPoints += payload.SellPrice;
+        addFusionPoints(inventory, payload.SellPrice);
     } else if (payload.SellCurrency == "SC_PrimeBucks") {
         addMiscItems(inventory, [
             {
diff --git a/src/controllers/custom/addCurrencyController.ts b/src/controllers/custom/addCurrencyController.ts
index 63dedb6f..be14b8a3 100644
--- a/src/controllers/custom/addCurrencyController.ts
+++ b/src/controllers/custom/addCurrencyController.ts
@@ -1,12 +1,16 @@
 import { RequestHandler } from "express";
 import { getAccountIdForRequest } from "@/src/services/loginService";
-import { getInventory } from "@/src/services/inventoryService";
+import { addFusionPoints, getInventory } from "@/src/services/inventoryService";
 
 export const addCurrencyController: RequestHandler = async (req, res) => {
     const accountId = await getAccountIdForRequest(req);
-    const inventory = await getInventory(accountId);
     const request = req.body as IAddCurrencyRequest;
-    inventory[request.currency] += request.delta;
+    const inventory = await getInventory(accountId, request.currency);
+    if (request.currency == "FusionPoints") {
+        addFusionPoints(inventory, request.delta);
+    } else {
+        inventory[request.currency] += request.delta;
+    }
     await inventory.save();
     res.end();
 };
diff --git a/src/services/inventoryService.ts b/src/services/inventoryService.ts
index 9e89dcfe..51312029 100644
--- a/src/services/inventoryService.ts
+++ b/src/services/inventoryService.ts
@@ -580,7 +580,7 @@ export const addItem = async (
     }
     if (typeName in ExportFusionBundles) {
         const fusionPointsTotal = ExportFusionBundles[typeName].fusionPoints * quantity;
-        inventory.FusionPoints += fusionPointsTotal;
+        addFusionPoints(inventory, fusionPointsTotal);
         return {
             FusionPoints: fusionPointsTotal
         };
@@ -1069,6 +1069,15 @@ export const updateCurrency = (
     return currencyChanges;
 };
 
+export const addFusionPoints = (inventory: TInventoryDatabaseDocument, add: number): number => {
+    if (inventory.FusionPoints + add > 2147483647) {
+        logger.warn(`capping FusionPoints balance at 2147483647`);
+        add = 2147483647 - inventory.FusionPoints;
+    }
+    inventory.FusionPoints += add;
+    return add;
+};
+
 const standingLimitBinToInventoryKey: Record<
     Exclude<TStandingLimitBin, "STANDING_LIMIT_BIN_NONE">,
     keyof IDailyAffiliations
diff --git a/src/services/missionInventoryUpdateService.ts b/src/services/missionInventoryUpdateService.ts
index f03dda81..05b94b0a 100644
--- a/src/services/missionInventoryUpdateService.ts
+++ b/src/services/missionInventoryUpdateService.ts
@@ -19,6 +19,7 @@ import {
     addCrewShipRawSalvage,
     addEmailItem,
     addFocusXpIncreases,
+    addFusionPoints,
     addFusionTreasures,
     addGearExpByCategory,
     addItem,
@@ -287,14 +288,14 @@ export const addMissionInventoryUpdates = async (
                 addShipDecorations(inventory, value);
                 break;
             case "FusionBundles": {
-                let fusionPoints = 0;
+                let fusionPointsDelta = 0;
                 for (const fusionBundle of value) {
-                    const fusionPointsTotal =
-                        ExportFusionBundles[fusionBundle.ItemType].fusionPoints * fusionBundle.ItemCount;
-                    inventory.FusionPoints += fusionPointsTotal;
-                    fusionPoints += fusionPointsTotal;
+                    fusionPointsDelta += addFusionPoints(
+                        inventory,
+                        ExportFusionBundles[fusionBundle.ItemType].fusionPoints * fusionBundle.ItemCount
+                    );
                 }
-                inventoryChanges.FusionPoints = fusionPoints;
+                inventoryChanges.FusionPoints = fusionPointsDelta;
                 break;
             }
             case "EmailItems": {