diff --git a/AutoRest/Generators/Ruby/Azure.Ruby/AzureRubyCodeGenerator.cs b/AutoRest/Generators/Ruby/Azure.Ruby/AzureRubyCodeGenerator.cs
index 1f2061affd..42c6686cc0 100644
--- a/AutoRest/Generators/Ruby/Azure.Ruby/AzureRubyCodeGenerator.cs
+++ b/AutoRest/Generators/Ruby/Azure.Ruby/AzureRubyCodeGenerator.cs
@@ -141,7 +141,7 @@ public override async Task Generate(ServiceClient serviceClient)
             // Requirements
             var requirementsTemplate = new RequirementsTemplate
             {
-                Model = new AzureRequirementsTemplateModel(serviceClient, this.packageName ?? this.sdkName, this.ImplementationFileExtension),
+                Model = new AzureRequirementsTemplateModel(serviceClient, this.packageName ?? this.sdkName, this.ImplementationFileExtension, this.Settings.Namespace),
             };
             await Write(requirementsTemplate, RubyCodeNamer.UnderscoreCase(this.packageName ?? this.sdkName) + ImplementationFileExtension);
                 
diff --git a/AutoRest/Generators/Ruby/Azure.Ruby/TemplateModels/AzureRequirementsTemplateModel.cs b/AutoRest/Generators/Ruby/Azure.Ruby/TemplateModels/AzureRequirementsTemplateModel.cs
index 2b20dab125..345d6e2f7e 100644
--- a/AutoRest/Generators/Ruby/Azure.Ruby/TemplateModels/AzureRequirementsTemplateModel.cs
+++ b/AutoRest/Generators/Ruby/Azure.Ruby/TemplateModels/AzureRequirementsTemplateModel.cs
@@ -30,8 +30,9 @@ protected override bool ExcludeModel(CompositeType model)
         /// <param name="serviceClient">The service client (main point of access to SDK).</param>
         /// <param name="sdkName">The name of the generated SDK, required for proper folder structuring.</param>
         /// <param name="filesExtension">The files extension.</param>
-        public AzureRequirementsTemplateModel(ServiceClient serviceClient, string sdkName, string filesExtension)
-            : base(serviceClient, sdkName, filesExtension)
+        /// <param name="ns">The namespace of the SDK.</param>
+        public AzureRequirementsTemplateModel(ServiceClient serviceClient, string sdkName, string filesExtension, string ns)
+            : base(serviceClient, sdkName, filesExtension, ns)
         {
         }
 
diff --git a/AutoRest/Generators/Ruby/Ruby/RubyCodeGenerator.cs b/AutoRest/Generators/Ruby/Ruby/RubyCodeGenerator.cs
index 31821f2795..5b875665df 100644
--- a/AutoRest/Generators/Ruby/Ruby/RubyCodeGenerator.cs
+++ b/AutoRest/Generators/Ruby/Ruby/RubyCodeGenerator.cs
@@ -189,12 +189,12 @@ await Write(enumTemplate,
             // Requirements
             var requirementsTemplate = new RequirementsTemplate
             {
-                Model = new RequirementsTemplateModel(serviceClient, this.packageName ?? this.sdkName, this.ImplementationFileExtension),
+                Model = new RequirementsTemplateModel(serviceClient, this.packageName ?? this.sdkName, this.ImplementationFileExtension, this.Settings.Namespace),
             };
             await Write(requirementsTemplate, RubyCodeNamer.UnderscoreCase(this.packageName ?? this.sdkName) + ImplementationFileExtension);
                 
             // Version File
-            if(this.packageVersion != null)
+            if(!string.IsNullOrEmpty(this.packageVersion))
             {
                 var versionTemplate = new VersionTemplate
                 {
@@ -204,7 +204,7 @@ await Write(enumTemplate,
             }
             
             // Module Definition File
-            if(Settings.Namespace != null)
+            if(!string.IsNullOrEmpty(Settings.Namespace))
             {
                 var modTemplate = new ModuleDefinitionTemplate
                 {
diff --git a/AutoRest/Generators/Ruby/Ruby/TemplateModels/RequirementsTemplateModel.cs b/AutoRest/Generators/Ruby/Ruby/TemplateModels/RequirementsTemplateModel.cs
index ed1534776a..6fbcf8e55a 100644
--- a/AutoRest/Generators/Ruby/Ruby/TemplateModels/RequirementsTemplateModel.cs
+++ b/AutoRest/Generators/Ruby/Ruby/TemplateModels/RequirementsTemplateModel.cs
@@ -6,6 +6,8 @@
 using System.Text;
 using Microsoft.Rest.Generator.ClientModel;
 using Microsoft.Rest.Generator.Utilities;
+using System;
+using System.Globalization;
 
 namespace Microsoft.Rest.Generator.Ruby
 {
@@ -28,6 +30,12 @@ public class RequirementsTemplateModel : ServiceClient
         /// Files extensions.
         /// </summary>
         private readonly string implementationFileExtension;
+        
+        /// <summary>
+        /// Namspace of the service client.
+        /// </summary>
+        private readonly string ns;
+
 
         /// <summary>
         /// Returns the ordered list of models. Ordered means that if some model has
@@ -98,9 +106,11 @@ protected virtual bool ExcludeModel(CompositeType model)
         /// <param name="serviceClient">The service client.</param>
         /// <param name="sdkName">The name of the SDK.</param>
         /// <param name="implementationFileExtension">The files extension.</param>
-        public RequirementsTemplateModel(ServiceClient serviceClient, string sdkName, string implementationFileExtension)
+        /// <param name="ns">The namespace of the SDK.</param>
+        public RequirementsTemplateModel(ServiceClient serviceClient, string sdkName, string implementationFileExtension, string ns)
         {
             this.LoadFrom(serviceClient);
+            this.ns = ns;
             this.sdkName = sdkName;
             this.implementationFileExtension = implementationFileExtension;
         }
@@ -151,7 +161,7 @@ public string GetModelsRequiredFiles()
         /// <returns>The list of 'required' gems in form of string.</returns>
         public virtual string GetDependencyGems()
         {
-            return @"require 'uri'
+            var requirements = @"require 'uri'
 require 'cgi'
 require 'date'
 require 'json'
@@ -164,6 +174,16 @@ public virtual string GetDependencyGems()
 require 'faraday-cookie_jar'
 require 'concurrent'
 require 'ms_rest'";
+            if(!string.IsNullOrEmpty(this.ns))
+            {
+                return requirements 
+                    + Environment.NewLine 
+                    + string.Format(CultureInfo.InvariantCulture, "require '{0}/module_definition'", this.sdkName);
+            }
+            else
+            {
+                return requirements;
+            }
         }
     }
 }
diff --git a/ChangeLog.md b/ChangeLog.md
index 23a345a70f..c4affb34a9 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,6 @@
+## VNext (not released yet)
+* Fix ruby require module_definition if namespace is specified. See [#831](https://github.com/Azure/autorest/issues/831)
+
 ##2016.03.04 Version 0.15.0
 * Added Java code generator!
 * Added support for constants whenever parameters or properties are marked as required and have only one enum value (#281, #488)