diff --git a/packages/sdk/src/models/market.ts b/packages/sdk/src/models/market.ts
index 4257a2d..6d55627 100644
--- a/packages/sdk/src/models/market.ts
+++ b/packages/sdk/src/models/market.ts
@@ -54,7 +54,7 @@ class Market {
   /** Timestamp at which market should end */
   public end: BigInt;
 
-  public mdm: MarketDisputeMechanism;
+  public disputeMechanism: MarketDisputeMechanism;
   /** The description of the market. */
   public description: string;
   /** The market question. */
@@ -93,7 +93,7 @@ class Market {
       status: this.status,
       report: this.report,
       resolvedOutcome: this.resolvedOutcome,
-      mdm: this.mdm,
+      disputeMechanism: this.disputeMechanism,
       outcomeAssets: this.outcomeAssets,
       end: this.end,
     } = market);
diff --git a/packages/sdk/src/types/guards.ts b/packages/sdk/src/types/guards.ts
new file mode 100644
index 0000000..cd99f12
--- /dev/null
+++ b/packages/sdk/src/types/guards.ts
@@ -0,0 +1,10 @@
+import { AuthorisedDisputeMechanism, MarketDisputeMechanism } from ".";
+
+export const isAuthorisedDisputeMechanism = (
+  marketDisputeMechanism: MarketDisputeMechanism
+): marketDisputeMechanism is AuthorisedDisputeMechanism => {
+  return (
+    (marketDisputeMechanism as AuthorisedDisputeMechanism).authorized !==
+    undefined
+  );
+};
diff --git a/packages/sdk/src/types/index.ts b/packages/sdk/src/types/index.ts
index 5f708d8..cbd38ab 100644
--- a/packages/sdk/src/types/index.ts
+++ b/packages/sdk/src/types/index.ts
@@ -122,7 +122,7 @@ export type MarketResponse = {
   status: string;
   report: Report | null;
   resolvedOutcome: OutcomeReport | null;
-  mdm: MarketDisputeMechanism;
+  disputeMechanism: MarketDisputeMechanism;
   outcomeAssets: Asset[];
   end: BigInt;
 };
@@ -189,10 +189,16 @@ export type MarketTypeOf = { Categorical: number } | { Scalar: number[] };
 
 export type ScoringRule = "CPMM" | "RikiddoSigmoidFeeMarketEma";
 
+export type AuthorisedDisputeMechanism = { authorized: string };
+
+export type CourtDisputeMechanism = { Court: null };
+
+export type SimpleDisputeMechanism = { SimpleDisputes: null };
+
 export type MarketDisputeMechanism =
-  | { Authorized: number }
-  | { Court: null }
-  | { SimpleDisputes: null };
+  | AuthorisedDisputeMechanism
+  | CourtDisputeMechanism
+  | SimpleDisputeMechanism;
 
 export type MarketDispute = {
   at: number;
@@ -314,3 +320,5 @@ export type ActiveAssetsResponse = {
   qty: string;
   price: number;
 }[];
+
+export * from "./guards";