diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5695028..a70aaf1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,21 @@ For a human friendly description of what changed in each release, take a look
 at the [Releases](https://github.com/SierraSoftworks/Iridium/releases) page.
 
 
+## Version [7.2.1](https://github.com/SierraSoftworks/Iridium/releases/tag/v7.2.1)
+<a style="border-radius: 2px; padding: 4px 8px; background: rgb(64, 120, 192); color: #fff;" href="https://github.com/SierraSoftworks/Iridium/releases/tag/v7.2.1">tag: **v7.2.1**</a>
+
+```sh
+npm install iridium@7.2.1
+```
+
+### Changes
+ - [8bc77dd](https://github.com/SierraSoftworks/Iridium/commit/8bc77dd) 7.2.1
+ - [f5e543f](https://github.com/SierraSoftworks/Iridium/commit/f5e543f) style: Improve error message for missing mapReduceOptions on instance
+ - [23a3d1a](https://github.com/SierraSoftworks/Iridium/commit/23a3d1a) Merge pull request #78 from RagibHasin/master
+ - [5eb054f](https://github.com/SierraSoftworks/Iridium/commit/5eb054f) Fix code quality with mapReduce
+ - [c79b2a4](https://github.com/SierraSoftworks/Iridium/commit/c79b2a4) Fix mapReduce reduce function return type, mapReduce parameter validation and add new tests
+ - [db0d44e](https://github.com/SierraSoftworks/Iridium/commit/db0d44e) doc: Update changelog
+
 ## Version [7.2.0](https://github.com/SierraSoftworks/Iridium/releases/tag/v7.2.0)
 <a style="border-radius: 2px; padding: 4px 8px; background: rgb(64, 120, 192); color: #fff;" href="https://github.com/SierraSoftworks/Iridium/releases/tag/v7.2.0">tag: **v7.2.0**</a>
 
diff --git a/doc b/doc
index 613dd0d..e71feb5 160000
--- a/doc
+++ b/doc
@@ -1 +1 @@
-Subproject commit 613dd0d4cd8488b9150f55bda9db6e3ffff97b05
+Subproject commit e71feb500c6776868c760d4b0d5abbb451a35c65
diff --git a/lib/MapReduce.ts b/lib/MapReduce.ts
index b630c60..38c65de 100644
--- a/lib/MapReduce.ts
+++ b/lib/MapReduce.ts
@@ -35,7 +35,7 @@ export interface MapFunction<TDocument> {
  * @param {Value[]} values The values to reduce
  */
 export interface ReduceFunction<Key, Value> {
-    (key: Key, values: Value[]): Value
+    (key: Key, values: Value[]): Value | Value[] | any
 }
 
 /**
diff --git a/lib/Model.ts b/lib/Model.ts
index c68fb21..c9d9817 100644
--- a/lib/Model.ts
+++ b/lib/Model.ts
@@ -271,7 +271,7 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
         conditions = this._helpers.convertToDB(conditions);
 
         let cursor = this.collection.find(conditions);
-        
+
         if(fields)
             cursor = cursor.project(fields);
 
@@ -383,18 +383,18 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
             if (cachedDocument) return cachedDocument;
             return new Bluebird<TDocument|null>((resolve, reject) => {
                 let cursor = this.collection.find(conditions);
-                    
+
                 if(options!.sort)
                     cursor = cursor.sort(options!.sort!);
-                
+
                 if(typeof options!.skip === "number")
                     cursor = cursor.skip(options!.skip!);
-                
+
                 cursor = cursor.limit(1);
-                    
+
                 if(options!.fields)
                     cursor = cursor.project(options!.fields!);
-                
+
                 return cursor.next((err, result) => {
                     if (err) return reject(err);
                     return resolve(result);
@@ -573,7 +573,7 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
 
                 if (opts.multi)
                     return this.collection.updateMany(conditions, changes, opts, callback);
-                
+
                 return this.collection.updateOne(conditions, changes, opts, callback)
             })
         }).nodeify(callback);
@@ -671,7 +671,7 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
                     if (err) return reject(err);
                     return resolve(response.result.n);
                 });
-                
+
                 this.collection.deleteMany(conditions, options!, (err, response) => {
                     if (err) return reject(err);
                     return resolve(response.result.n);
@@ -706,11 +706,12 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
      * @param options Options used to configure how MongoDB runs the mapReduce operation on your collection.
      * @return A promise which completes when the mapReduce operation has written its results to the provided collection.
      */
-    mapReduce<Key, Value>(instanceType: InstanceImplementation<MapReducedDocument<Key, Value>, any> & { mapReduceOptions: MapReduceFunctions<TDocument, Key, Value> },
+    mapReduce<Key, Value>(instanceType: InstanceImplementation<MapReducedDocument<Key, Value>, any>,
         options: MapReduceOptions): Bluebird<void>;
-    mapReduce<Key, Value>(functions: (InstanceImplementation<MapReducedDocument<Key, Value>, any> & { mapReduceOptions: MapReduceFunctions<TDocument, Key, Value> }) |
+    mapReduce<Key, Value>(functions: InstanceImplementation<MapReducedDocument<Key, Value>, any> |
         MapReduceFunctions<TDocument, Key, Value>, options: MapReduceOptions) {
         type fn = MapReduceFunctions<TDocument, Key, Value>;
+        type instance = InstanceImplementation<MapReducedDocument<Key, Value>, any>
 
         if ((<fn>functions).map) {
             return new Bluebird<MapReducedDocument<Key, Value>[]>((resolve, reject) => {
@@ -725,10 +726,12 @@ export class Model<TDocument extends { _id?: any }, TInstance> {
             })
         }
         else {
-            let instanceType = <InstanceImplementation<MapReducedDocument<Key, Value>, any> & { mapReduceOptions: MapReduceFunctions<TDocument, Key, Value> }>functions;
+            let instanceType = <instance>functions;
             return new Bluebird<void>((resolve, reject) => {
                 if (options.out && options.out == "inline")
                     return reject(new Error("Expected a non-inline mapReduce output mode for this method signature"));
+                if (!instanceType.mapReduceOptions)
+                    return reject(new Error("Expected mapReduceOptions to be specified on the instance type"));
                 let opts = <MongoDB.MapReduceOptions>options;
                 let out : {[op: string]: string} = {};
                 out[(<string>options.out)] = instanceType.collection;
diff --git a/package.json b/package.json
index 389f64f..6c5df9f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "iridium",
-  "version": "7.2.0",
+  "version": "7.2.1",
   "author": "Benjamin Pannell <admin@sierrasoftworks.com>",
   "description": "A custom lightweight ORM for MongoDB designed for power-users",
   "license": "MIT",
diff --git a/test/MapReduce.ts b/test/MapReduce.ts
index cbbf23d..c4191f6 100644
--- a/test/MapReduce.ts
+++ b/test/MapReduce.ts
@@ -44,6 +44,23 @@ class MapReducedInstance extends Iridium.Instance<Iridium.MapReducedDocument<str
     value: number;
 }
 
+@Iridium.MapReduce(function (this: TestDocument) {
+    emit(this.cust_id, this.amount);
+}, function (key: string, values: number[]) {
+    return values.reduce((sum, val) => sum + val, 0);
+})
+class DecoratedMapReducedInstance extends Iridium.Instance<Iridium.MapReducedDocument<string, number>, MapReducedInstance>{
+    static collection = "decoratedMapReduced";
+    _id: string;
+    value: number;
+}
+
+class NotMapReducedInstance extends Iridium.Instance<Iridium.MapReducedDocument<string, number>, MapReducedInstance>{
+    static collection = "notMapReduced";
+    _id: string;
+    value: number;
+}
+
 describe("Model", () => {
     let core = new Iridium.Core({ database: "test" });
 
@@ -61,6 +78,14 @@ describe("Model", () => {
             ]));
         });
 
+        it("should correctly map and reduce with model and decorator", () => {
+            let reducedModel = new Iridium.Model<Iridium.MapReducedDocument<string, number>, DecoratedMapReducedInstance>(core, DecoratedMapReducedInstance);
+            let t = reducedModel.remove().then(() => model.mapReduce(DecoratedMapReducedInstance, {
+                out: "replace", query: { status: "A" }
+            }).then(() => reducedModel.find().toArray()));
+            return chai.expect(t).to.eventually.exist.and.have.length(2);
+        });
+
         it("should correctly map and reduce with model", () => {
             let reducedModel = new Iridium.Model<Iridium.MapReducedDocument<string, number>, MapReducedInstance>(core, MapReducedInstance);
             let t = reducedModel.remove().then(() => model.mapReduce(MapReducedInstance, {
@@ -97,5 +122,12 @@ describe("Model", () => {
             });
             return chai.expect(t).to.eventually.be.rejected;
         });
+
+        it("should reject with no mapReduce info in Instance type", () => {
+            let t = model.mapReduce(NotMapReducedInstance, {
+                out: "replace", query: { status: "A" }
+            });
+            return chai.expect(t).to.eventually.be.rejected;
+        });
     });
 });
\ No newline at end of file