diff --git a/README.md b/README.md
index a55cf90..6e617d8 100644
--- a/README.md
+++ b/README.md
@@ -11,9 +11,11 @@ Import-Module set-display-resolution.psm1
 
 Usage:
 ``` powershell
-Set-DisplayResolution(1024,768,CDSFlags.SetPrimary);
+Set-DisplayResolution -Width 1024 -Height 768
+Set-DisplayResolution -Width 1024 -Height 768 -RefreshRate 60
+Set-DisplayResolution -Width 1024 -Height 768 -RefreshRate 60 -flag "t"
 
-write-host Get-DisplayResolution()
+Get-DisplayResolution
 ```
 
 ## .Net Tool
@@ -37,6 +39,8 @@ ChangeDisplaySettings --help
 
   -h, --height    Required. Height of the screen
 
+  -r, --refreshrate Optional. Refresh rate of the screen
+
   -t, --test      (Default: false) Test resolution change or actually perform the change.
 
   --help          Display this help screen.
diff --git a/cds/DisplaySettings/CDS.cs b/cds/DisplaySettings/CDS.cs
index f885f91..cae1599 100644
--- a/cds/DisplaySettings/CDS.cs
+++ b/cds/DisplaySettings/CDS.cs
@@ -43,6 +43,7 @@ public struct DEVMODE
     /// </summary>
     public class Helper
     {
+        #nullable enable
 
         /// <summary>
         /// Gets the display settings.
@@ -70,11 +71,12 @@ public static DEVMODE GetDisplaySettings()
         /// </summary>
         /// <param name="width">The width.</param>
         /// <param name="height">The height.</param>
+        /// <param name="refreshrate">The refresh rate.</param>
         /// <param name="flags">The flags.</param>
         /// <returns></returns>
-        public static string ChangeDisplaySettings(int width, int height, Flags flags)
+        public static string ChangeDisplaySettings(int width, int height, int refreshrate, Flags flags)
         {
-            return ChangeDisplaySettings(width, height, flags, out var _);
+            return ChangeDisplaySettings(width, height, refreshrate, flags, out var _);
         }
 
         /// <summary>
@@ -82,10 +84,11 @@ public static string ChangeDisplaySettings(int width, int height, Flags flags)
         /// </summary>
         /// <param name="width">The width.</param>
         /// <param name="height">The height.</param>
+        /// <param name="refreshrate">The refresh rate.</param>
         /// <param name="flags">The flags.</param>
         /// <param name="success">if set to <c>true</c> the change was successful.</param>
         /// <returns></returns>
-        public static string ChangeDisplaySettings(int width, int height, Flags flags, out bool success)
+        public static string ChangeDisplaySettings(int width, int height, int refreshrate, Flags flags, out bool success)
         {
             // /* Return values for ChangeDisplaySettings */
             // #define DISP_CHANGE_SUCCESSFUL       0
@@ -103,7 +106,9 @@ public static string ChangeDisplaySettings(int width, int height, Flags flags, o
 
             devMode.dmPelsWidth = width;
             devMode.dmPelsHeight = height;
-
+            if (refreshrate > 0) {
+                devMode.dmDisplayFrequency = refreshrate;
+            }
             var res = ChangeDisplaySettings(ref devMode, (int)flags);
             success = false;
             switch (res)
@@ -137,7 +142,7 @@ public static string ChangeDisplaySettings(int width, int height, Flags flags, o
         private static extern int ChangeDisplaySettings(ref DEVMODE devMode, int flags);
 
         /// <summary>
-        /// Resolution chgange flags
+        /// Resolution change flags
         /// </summary>
         [Flags]
         public enum Flags:int
diff --git a/cds/DisplaySettings/DisplaySettings.psd1 b/cds/DisplaySettings/DisplaySettings.psd1
index 7b77078..dc87e03 100644
--- a/cds/DisplaySettings/DisplaySettings.psd1
+++ b/cds/DisplaySettings/DisplaySettings.psd1
@@ -12,7 +12,7 @@
     RootModule        = './set-display-resolution.psm1'
 
     # Version number of this module.
-    ModuleVersion     = '0.0.2'
+    ModuleVersion     = '0.0.4'
 
     # Supported PSEditions
     # CompatiblePSEditions = @()
diff --git a/cds/DisplaySettings/set-display-resolution.psm1 b/cds/DisplaySettings/set-display-resolution.psm1
index 796fb2d..4672811 100644
--- a/cds/DisplaySettings/set-display-resolution.psm1
+++ b/cds/DisplaySettings/set-display-resolution.psm1
@@ -23,11 +23,15 @@ function Set-DisplayResolution {
         [int] 
         $Height,
 
+        [Parameter(Mandatory = $false, Position = 2)] 
+        [int] 
+        $RefreshRate=0,
+
         [CDSFlags]
         $Flag = [CDSFlags]::Dynamically
     )
     
-    [cds.Helper]::ChangeDisplaySettings($width, $height, $flag)
+    [cds.Helper]::ChangeDisplaySettings($width, $height, $refreshrate, $flag)
 }
 
 function Get-DisplayResolution {
diff --git a/cds/Program.cs b/cds/Program.cs
index 7fe1273..a2c1960 100644
--- a/cds/Program.cs
+++ b/cds/Program.cs
@@ -1,5 +1,6 @@
 using CommandLine;
 using System;
+using System.ComponentModel;
 using System.ComponentModel.DataAnnotations;
 
 namespace cds
@@ -14,6 +15,7 @@ static int Main(string[] args)
                    string res = Helper.ChangeDisplaySettings(
                                         o.Width,
                                         o.Height,
+                                        o.RefreshRate,
                                         o.Test
                                             ? Helper.Flags.CDS_TEST
                                             : Helper.Flags.CDS_SET_PRIMARY,
@@ -56,6 +58,16 @@ public class Options
         [Option('h', "height", Required = true, HelpText = "Height of the screen")]
         public int Height { get; set; }
 
+        /// <summary>
+        /// Gets or sets the refresh rate.
+        /// </summary>
+        /// <value>
+        /// The refresh rate.
+        /// </value>
+        [Range(1, int.MaxValue)]
+        [Option('r', "refreshrate", Required = false, HelpText = "Refresh rate of the screen", Default = 0)]
+        public int RefreshRate { get; set; }
+
         /// <summary>
         /// Test resolution change or actually perform.
         /// </summary>
diff --git a/cds/cds.csproj b/cds/cds.csproj
index d0b1a42..ccb6923 100644
--- a/cds/cds.csproj
+++ b/cds/cds.csproj
@@ -6,11 +6,11 @@
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
     <Title>Change Display Settings</Title>
     <Description>Sets display resolution info on Windows</Description>
-    <Authors>jiajun.qian, Robert Sirre</Authors>
+    <Authors>jiajun.qian, Robert Sirre, Samuel Zamvil</Authors>
     <StartupObject>cds.Program</StartupObject>
     <Nullable>enable</Nullable>
     <GenerateDocumentationFile>True</GenerateDocumentationFile>
-    <Version>0.0.3</Version>
+    <Version>0.0.4</Version>
     <ToolCommandName>ChangeDisplaySettings</ToolCommandName>
     <TreatWarningsAsErrors>True</TreatWarningsAsErrors>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
@@ -27,6 +27,7 @@
     <PackageReadmeFile>README.md</PackageReadmeFile>
     <PackageTags>Screen Resolution;Display Resolution;Resolution</PackageTags>
     <PackageReleaseNotes>
+      0.0.4: Added support for setting the refresh rate.
       0.0.3: Used more appropriate command 'ChangeDisplaySettings' instead of 'ChangeDisplayResolution', which is better suited to later improvements.
       0.0.2: First release as .Net tool</PackageReleaseNotes>
     <NeutralLanguage>en-US</NeutralLanguage>
diff --git a/cds_legacy/DisplaySettings.Powershell.51.Compatible/CDS.cs b/cds_legacy/DisplaySettings.Powershell.51.Compatible/CDS.cs
new file mode 100644
index 0000000..c0ca54e
--- /dev/null
+++ b/cds_legacy/DisplaySettings.Powershell.51.Compatible/CDS.cs
@@ -0,0 +1,115 @@
+namespace cds
+{
+    using System;
+    using System.Runtime.InteropServices;
+
+    [StructLayout(LayoutKind.Explicit)]
+    public struct DEVMODE
+    {
+        [FieldOffset(102)]
+        public short dmLogPixels;
+        [FieldOffset(104)]
+        public int dmBitsPerPel;
+        [FieldOffset(108)]
+        public int dmPelsWidth;
+        [FieldOffset(112)]
+        public int dmPelsHeight;
+        [FieldOffset(116)]
+        public int dmDisplayFlags;
+        [FieldOffset(120)]
+        public int dmDisplayFrequency;
+    }
+
+
+    // https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-changedisplaysettingsa
+    public class Helper
+    {
+        public static DEVMODE GetDisplaySettings()
+        {
+            // #define ENUM_CURRENT_SETTINGS       ((DWORD)-1)
+            // #define ENUM_REGISTRY_SETTINGS      ((DWORD)-2)
+            var devMode = new DEVMODE();
+
+            // A NULL value specifies the current display device on the computer on which the calling thread is running.
+            var retCode = EnumDisplaySettings(null, -1, ref devMode);
+            if (retCode == 0)
+            {
+                throw new Exception("can't get resolution from win api");
+            }
+
+            return devMode;
+        }
+
+        public static string ChangeDisplaySettings(int width, int height, int refreshrate, int flags)
+        {
+            // /* Return values for ChangeDisplaySettings */
+            // #define DISP_CHANGE_SUCCESSFUL       0
+            // #define DISP_CHANGE_RESTART          1
+            // #define DISP_CHANGE_FAILED          -1
+            // #define DISP_CHANGE_BADMODE         -2
+            // #define DISP_CHANGE_NOTUPDATED      -3
+            // #define DISP_CHANGE_BADFLAGS        -4
+            // #define DISP_CHANGE_BADPARAM        -5
+            // #if(_WIN32_WINNT >= 0x0501)
+            // #define DISP_CHANGE_BADDUALVIEW     -6
+            // #endif /* _WIN32_WINNT >= 0x0501 */
+
+            var devMode = GetDisplaySettings();
+
+            devMode.dmPelsWidth = width;
+            devMode.dmPelsHeight = height;
+
+            if (refreshrate > 0) {
+                devMode.dmDisplayFrequency = refreshrate;
+            }
+
+            var res = ChangeDisplaySettings(ref devMode, flags);
+            switch (res)
+            {
+                case 0:
+                    return "The settings change was successful.";
+                case 1:
+                    return "The computer must be restarted for the graphics mode to work.";
+                case -1:
+                    return "The display driver failed the specified graphics mode.";
+                case -2:
+                    return "The graphics mode is not supported.";
+                case -3:
+                    return "Unable to write settings to the registry.";
+                case -4:
+                    return "An invalid set of flags was passed in.";
+                case -5:
+                    return "An invalid parameter was passed in. This can include an invalid flag or combination of flags.";
+                case -6:
+                    return "The settings change was unsuccessful because the system is DualView capable.";
+                default:
+                    return "unknow return code: " + res;
+            }
+        }
+
+        [DllImport("user32.dll")]
+        static extern int EnumDisplaySettings(string deviceName, int modeNum, ref DEVMODE devMode);
+
+        [DllImport("user32.dll")]
+        public static extern int ChangeDisplaySettings(ref DEVMODE devMode, int flags);
+
+        public class Flags
+        {
+            // #define CDS_UPDATEREGISTRY           0x00000001
+            // #define CDS_TEST                     0x00000002
+            // #define CDS_FULLSCREEN               0x00000004
+            // #define CDS_GLOBAL                   0x00000008
+            // #define CDS_SET_PRIMARY              0x00000010
+            // #define CDS_RESET                    0x40000000
+            // #define CDS_NORESET                  0x10000000
+
+            public const int CDS_UPDATEREGISTRY = 0x01;
+            public const int CDS_TEST = 0x02;
+            public const int CDS_FULLSCREEN = 0x04;
+            public const int CDS_GLOBAL = 0x08;
+            public const int CDS_SET_PRIMARY = 0x10;
+            public const int CDS_RESET = 0x40000000;
+            public const int CDS_NORESET = 0x10000000;
+        }
+    }
+}
\ No newline at end of file
diff --git a/cds_legacy/DisplaySettings.Powershell.51.Compatible/DisplaySettings.psd1 b/cds_legacy/DisplaySettings.Powershell.51.Compatible/DisplaySettings.psd1
new file mode 100644
index 0000000..dc87e03
--- /dev/null
+++ b/cds_legacy/DisplaySettings.Powershell.51.Compatible/DisplaySettings.psd1
@@ -0,0 +1,132 @@
+#
+# Module manifest for module 'DisplaySettings'
+#
+# Generated by: jiajun.qian
+#
+# Generated on: 7/21/2020
+#
+
+@{
+
+    # Script module or binary module file associated with this manifest.
+    RootModule        = './set-display-resolution.psm1'
+
+    # Version number of this module.
+    ModuleVersion     = '0.0.4'
+
+    # Supported PSEditions
+    # CompatiblePSEditions = @()
+
+    # ID used to uniquely identify this module
+    GUID              = 'a0b9c4f9-1d76-48a4-8c2a-a29c65dfb1be'
+
+    # Author of this module
+    Author            = 'jiajun.qian'
+
+    # Company or vendor of this module
+    # CompanyName = 'Unknown'
+
+    # Copyright statement for this module
+    # Copyright = '(c) jiajun.qian. All rights reserved.'
+
+    # Description of the functionality provided by this module
+    Description       = 'get/set display resolution info on windows'
+
+    # Minimum version of the PowerShell engine required by this module
+    # PowerShellVersion = ''
+
+    # Name of the PowerShell host required by this module
+    # PowerShellHostName = ''
+
+    # Minimum version of the PowerShell host required by this module
+    # PowerShellHostVersion = ''
+
+    # Minimum version of Microsoft .NET Framework required by this module. This prerequisite is valid for the PowerShell Desktop edition only.
+    # DotNetFrameworkVersion = ''
+
+    # Minimum version of the common language runtime (CLR) required by this module. This prerequisite is valid for the PowerShell Desktop edition only.
+    # ClrVersion = ''
+
+    # Processor architecture (None, X86, Amd64) required by this module
+    # ProcessorArchitecture = ''
+
+    # Modules that must be imported into the global environment prior to importing this module
+    # RequiredModules = @()
+
+    # Assemblies that must be loaded prior to importing this module
+    # RequiredAssemblies = @()
+
+    # Script files (.ps1) that are run in the caller's environment prior to importing this module.
+    # ScriptsToProcess = @()
+
+    # Type files (.ps1xml) to be loaded when importing this module
+    # TypesToProcess = @()
+
+    # Format files (.ps1xml) to be loaded when importing this module
+    # FormatsToProcess = @()
+
+    # Modules to import as nested modules of the module specified in RootModule/ModuleToProcess
+    # NestedModules = @()
+
+    # Functions to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no functions to export.
+    FunctionsToExport = @("Set-DisplayResolution", "Get-DisplayResolution")
+
+    # Cmdlets to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no cmdlets to export.
+    CmdletsToExport   = @()
+
+    # Variables to export from this module
+    VariablesToExport = '*'
+
+    # Aliases to export from this module, for best performance, do not use wildcards and do not delete the entry, use an empty array if there are no aliases to export.
+    AliasesToExport   = @()
+
+    # DSC resources to export from this module
+    # DscResourcesToExport = @()
+
+    # List of all modules packaged with this module
+    # ModuleList = @()
+
+    # List of all files packaged with this module
+    FileList          = @("./CDS.cs")
+
+    # Private data to pass to the module specified in RootModule/ModuleToProcess. This may also contain a PSData hashtable with additional module metadata used by PowerShell.
+    PrivateData       = @{
+
+        PSData = @{
+
+            # Tags applied to this module. These help with module discovery in online galleries.
+            Tags       = @("ScreenResolution", "DisplayResolution")
+
+            # A URL to the license for this module.
+            LicenseUri = 'https://github.com/lust4life/display-resolution/blob/master/LICENSE'
+
+            # A URL to the main website for this project.
+            ProjectUri = 'https://github.com/lust4life/display-resolution'
+
+            # A URL to an icon representing this module.
+            # IconUri = ''
+
+            # ReleaseNotes of this module
+            # ReleaseNotes = ''
+
+            # Prerelease string of this module
+            # Prerelease = ''
+
+            # Flag to indicate whether the module requires explicit user acceptance for install/update/save
+            # RequireLicenseAcceptance = $false
+
+            # External dependent modules of this module
+            # ExternalModuleDependencies = @()
+
+        } # End of PSData hashtable
+
+    } # End of PrivateData hashtable
+
+    # HelpInfo URI of this module
+    # HelpInfoURI = ''
+
+    # Default prefix for commands exported from this module. Override the default prefix using Import-Module -Prefix.
+    # DefaultCommandPrefix = ''
+
+}
+
diff --git a/cds_legacy/DisplaySettings.Powershell.51.Compatible/set-display-resolution.psm1 b/cds_legacy/DisplaySettings.Powershell.51.Compatible/set-display-resolution.psm1
new file mode 100644
index 0000000..4672811
--- /dev/null
+++ b/cds_legacy/DisplaySettings.Powershell.51.Compatible/set-display-resolution.psm1
@@ -0,0 +1,42 @@
+[Flags()] enum CDSFlags {
+    Dynamically = 0
+    UpdateRegistry = 0x01
+    Test = 0x02
+    FullScreen = 0x04
+    Global = 0x08
+    SetPrimary = 0x10
+    Reset = 0x40000000
+    NoReset = 0x10000000
+}
+
+<#
+.LINK
+https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-changedisplaysettingsa#parameters
+#>
+function Set-DisplayResolution {
+    param (
+        [Parameter(Mandatory = $true, Position = 0)] 
+        [int] 
+        $Width, 
+
+        [Parameter(Mandatory = $true, Position = 1)] 
+        [int] 
+        $Height,
+
+        [Parameter(Mandatory = $false, Position = 2)] 
+        [int] 
+        $RefreshRate=0,
+
+        [CDSFlags]
+        $Flag = [CDSFlags]::Dynamically
+    )
+    
+    [cds.Helper]::ChangeDisplaySettings($width, $height, $refreshrate, $flag)
+}
+
+function Get-DisplayResolution {
+    [cds.Helper]::GetDisplaySettings()
+}
+
+$cds = Get-Content $PSScriptRoot/CDS.cs -Raw
+Add-Type -TypeDefinition $cds