diff --git a/packages/medusa/src/loaders/models.js b/packages/medusa/src/loaders/models.js
index 172378d550..35bfde28f4 100644
--- a/packages/medusa/src/loaders/models.js
+++ b/packages/medusa/src/loaders/models.js
@@ -19,7 +19,7 @@ export default ({ container }) => {
     const loaded = require(fn).default
     const name = formatRegistrationName(fn)
     container.register({
-      [name]: asFunction(cradle => new loaded(cradle)),
+      [name]: asFunction(cradle => new loaded(cradle)).singleton(),
     })
   })
 
@@ -37,7 +37,7 @@ export default ({ container }) => {
 
       const name = formatRegistrationName(fn)
       container.register({
-        [name]: asFunction(cradle => new loaded(cradle)),
+        [name]: asFunction(cradle => new loaded(cradle)).singleton(),
       })
     })
   }
diff --git a/packages/medusa/src/models/user.js b/packages/medusa/src/models/user.js
index bb7db1e712..ff65997438 100644
--- a/packages/medusa/src/models/user.js
+++ b/packages/medusa/src/models/user.js
@@ -9,7 +9,7 @@ class UserModel extends BaseModel {
   static modelName = "User"
   static schema = {
     email: { type: String, required: true },
-    passwordHash: { type: String, required: true },
+    passwordHash: { type: String },
     metadata: { type: mongoose.Schema.Types.Mixed, default: {} },
   }
 }