diff --git a/common/src/config/config.ts b/common/src/config/config.ts
index 1ea140fb3..39a6aad2d 100644
--- a/common/src/config/config.ts
+++ b/common/src/config/config.ts
@@ -2302,6 +2302,9 @@ const GAME_PT_CONFIGS: GamePTConfigs = {
 		profileRatingAlgFormatters: {},
 		sessionRatingAlgFormatters: {},
 
+		// This is quirky (lol)
+		// ITG difficulties can be any string they want to be. We just support some
+		// hardcoded defaults.
 		difficulties: ["Beginner", "Easy", "Medium", "Hard", "Challenge"],
 		shortDifficulties: {
 			Beginner: "B",
diff --git a/common/src/types.ts b/common/src/types.ts
index 44bf0fc65..edad2d848 100644
--- a/common/src/types.ts
+++ b/common/src/types.ts
@@ -337,7 +337,7 @@ export interface Difficulties {
 	"wacca:Single": "NORMAL" | "HARD" | "EXPERT" | "INFERNO";
 	"pms:Controller": "CHART";
 	"pms:Keyboard": "CHART";
-	"itg:Stamina": "Beginner" | "Easy" | "Medium" | "Hard" | "Challenge";
+	"itg:Stamina": string;
 }
 
 /**
@@ -829,6 +829,7 @@ interface ChartDocumentData {
 	"pms:Keyboard": CDDataBMS;
 	"itg:Stamina": {
 		chartHash: string;
+		difficultyTag: "Beginner" | "Easy" | "Medium" | "Hard" | "Challenge";
 		breakdown: {
 			detailed: string;
 			partiallySimplified: string;