diff --git a/package.json b/package.json
index c0a733f..74deb85 100644
--- a/package.json
+++ b/package.json
@@ -6,10 +6,11 @@
   "scripts": {
     "start": "npm run build && node ./lib/typegoose.js",
     "build": "rimraf lib && tsc",
+    "build:tests": "rimraf lib && cd src/test && tsc",
     "lint": "tslint --project tsconfig.json",
     "test": "npm run lint && npm run cover",
-    "mocha": "npm run build && mocha ./lib --recursive",
-    "cover": "npm run build && istanbul cover _mocha -- lib --recursive -R spec",
+    "mocha": "npm run build:tests && mocha ./lib --recursive",
+    "cover": "npm run build:tests && istanbul cover _mocha -- lib --recursive -R spec",
     "coveralls": "cat ./coverage/lcov.info | coveralls"
   },
   "repository": {
@@ -24,11 +25,11 @@
     "lodash": "4.17.10"
   },
   "peerDependencies": {
+    "@types/mongoose": "5.0.10",
     "mongoose": "^5.0.0",
     "reflect-metadata": "^0.1.8"
   },
   "devDependencies": {
-    "@types/mongoose": "5.0.10",
     "@types/chai": "4.1.3",
     "@types/dotenv": "4.0.3",
     "@types/lodash": "4.14.108",
diff --git a/src/prop.ts b/src/prop.ts
index dd4ea32..475d578 100644
--- a/src/prop.ts
+++ b/src/prop.ts
@@ -23,6 +23,7 @@ export interface BasePropOptions {
 
 export interface PropOptions extends BasePropOptions {
   ref?: any;
+  refType?: any;
 }
 
 export interface ValidateNumberOptions {
@@ -86,9 +87,13 @@ const baseProp = (rawOptions, Type, target, key, isArray = false) => {
 
   const ref = rawOptions.ref;
   if (ref) {
+    let refType = mongoose.Schema.Types.ObjectId;
+    if (rawOptions.refType) {
+      refType = rawOptions.refType;
+    }
     schema[name][key] = {
       ...schema[name][key],
-      type: mongoose.Schema.Types.ObjectId,
+      type: refType,
       ref: ref.name,
     };
     return;
@@ -96,9 +101,13 @@ const baseProp = (rawOptions, Type, target, key, isArray = false) => {
 
   const itemsRef = rawOptions.itemsRef;
   if (itemsRef) {
+    let refType = mongoose.Schema.Types.ObjectId;
+    if (rawOptions.refType) {
+      refType = rawOptions.refType;
+    }
     schema[name][key][0] = {
       ...schema[name][key][0],
-      type: mongoose.Schema.Types.ObjectId,
+      type: refType,
       ref: itemsRef.name,
     };
     return;
diff --git a/src/test/tsconfig.json b/src/test/tsconfig.json
new file mode 100644
index 0000000..dfd9f03
--- /dev/null
+++ b/src/test/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "include": [
+    "../**/*.ts"
+  ],
+  "exclude": [
+
+  ]
+}
diff --git a/tsconfig.json b/tsconfig.json
index c3aa0d4..5edff9b 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -11,5 +11,8 @@
   },
   "include": [
     "src/**/*.ts"
+  ],
+  "exclude": [
+    "src/test/**/*.ts"
   ]
 }