diff --git a/src/MongoMemoryServer.d.ts b/src/MongoMemoryServer.d.ts
index 98362c29b..5c340ae7a 100644
--- a/src/MongoMemoryServer.d.ts
+++ b/src/MongoMemoryServer.d.ts
@@ -29,7 +29,6 @@ export interface MongoInstanceDataT {
 }
 
 export default class MongoMemoryServer {
-  isRunning: boolean;
   runningInstance: Promise<MongoInstanceDataT> | undefined;
   opts: MongoMemoryServerOptsT;
   debug: DebugFn;
diff --git a/src/MongoMemoryServer.js b/src/MongoMemoryServer.js
index 4913de661..df06c4423 100644
--- a/src/MongoMemoryServer.js
+++ b/src/MongoMemoryServer.js
@@ -45,7 +45,6 @@ async function generateConnectionString(port: number, dbName: string): Promise<s
 }
 
 export default class MongoMemoryServer {
-  isRunning: boolean = false;
   runningInstance: ?Promise<MongoInstanceDataT>;
   opts: MongoMemoryServerOptsT;
   debug: DebugFn;