diff --git a/src/FSharp.UMX.fs b/src/FSharp.UMX.fs
index 3a25e05..c16c5e8 100644
--- a/src/FSharp.UMX.fs
+++ b/src/FSharp.UMX.fs
@@ -9,8 +9,10 @@ open System
 
 [<MeasureAnnotatedAbbreviation>] type bool<[<Measure>] 'm> = bool
 [<MeasureAnnotatedAbbreviation>] type byte<[<Measure>] 'm> = byte
+[<MeasureAnnotatedAbbreviation>] type uint16<[<Measure>] 'm> = uint16
 [<MeasureAnnotatedAbbreviation>] type uint64<[<Measure>] 'm> = uint64
 [<MeasureAnnotatedAbbreviation>] type Guid<[<Measure>] 'm> = Guid
+[<MeasureAnnotatedAbbreviation>] type char<[<Measure>] 'm> = char
 [<MeasureAnnotatedAbbreviation>] type string<[<Measure>] 'm> = string
 [<MeasureAnnotatedAbbreviation>] type TimeSpan<[<Measure>] 'm> = TimeSpan
 [<MeasureAnnotatedAbbreviation>] type DateTime<[<Measure>] 'm> = DateTime
@@ -18,6 +20,8 @@ open System
 #if NET6_0_OR_GREATER
 [<MeasureAnnotatedAbbreviation>] type DateOnly<[<Measure>] 'm> = DateOnly
 [<MeasureAnnotatedAbbreviation>] type TimeOnly<[<Measure>] 'm> = TimeOnly
+#else
+[<MeasureAnnotatedAbbreviation>] type uint32<[<Measure>] 'm> = uint32
 #endif
 
 module private Unsafe =
@@ -32,14 +36,17 @@ type UMX =
 
     static member inline tag<[<Measure>]'m> (x : bool) : bool<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : byte) : byte<'m> = Unsafe.cast x
+    static member inline tag<[<Measure>]'m> (x : sbyte) : sbyte<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : int) : int<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : int16) : int16<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : int64) : int64<'m> = Unsafe.cast x
+    static member inline tag<[<Measure>]'m> (x : uint16) : uint16<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : uint64) : uint64<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : float32) : float32<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : float) : float<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : decimal) : decimal<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : Guid) : Guid<'m> = Unsafe.cast x
+    static member inline tag<[<Measure>]'m> (x : char) : char<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : string) : string<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : TimeSpan) : TimeSpan<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : DateTime) : DateTime<'m> = Unsafe.cast x
@@ -47,18 +54,24 @@ type UMX =
 #if NET6_0_OR_GREATER
     static member inline tag<[<Measure>]'m> (x : DateOnly) : DateOnly<'m> = Unsafe.cast x
     static member inline tag<[<Measure>]'m> (x : TimeOnly) : TimeOnly<'m> = Unsafe.cast x
+    static member inline tag<[<Measure>]'m> (x : uint) : uint<'m> = Unsafe.cast x
+#else
+    static member inline tag<[<Measure>]'m> (x : uint32) : uint32<'m> = Unsafe.cast x
 #endif
 
     static member inline untag<[<Measure>]'m> (x : bool<'m>) : bool = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : byte<'m>) : byte = Unsafe.cast x
+    static member inline untag<[<Measure>]'m> (x : sbyte<'m>) : sbyte = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : int<'m>) : int = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : int16<'m>) : int16 = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : int64<'m>) : int64 = Unsafe.cast x
+    static member inline untag<[<Measure>]'m> (x : uint16<'m>) : uint16 = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : uint64<'m>) : uint64 = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : float32<'m>) : float32 = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : float<'m>) : float = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : decimal<'m>) : decimal = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : Guid<'m>) : Guid = Unsafe.cast x
+    static member inline untag<[<Measure>]'m> (x : char<'m>) : char = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : string<'m>) : string = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : TimeSpan<'m>) : TimeSpan = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : DateTime<'m>) : DateTime = Unsafe.cast x
@@ -66,18 +79,24 @@ type UMX =
 #if NET6_0_OR_GREATER
     static member inline untag<[<Measure>]'m> (x : DateOnly<'m>) : DateOnly = Unsafe.cast x
     static member inline untag<[<Measure>]'m> (x : TimeOnly<'m>) : TimeOnly = Unsafe.cast x
+    static member inline untag<[<Measure>]'m> (x : uint<'m>) : uint = Unsafe.cast x
+#else
+    static member inline untag<[<Measure>]'m> (x : uint32<'m>) : uint32 = Unsafe.cast x
 #endif
 
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : bool<'m1>) : bool<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : byte<'m1>) : byte<'m2> = Unsafe.cast x
+    static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : sbyte<'m1>) : sbyte<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : int<'m1>) : int<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : int16<'m1>) : int16<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : int64<'m1>) : int64<'m2> = Unsafe.cast x
+    static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : uint16<'m1>) : uint16<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : uint64<'m1>) : uint64<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : float<'m1>) : float<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : float32<'m1>) : float32<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : decimal<'m1>) : decimal<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : Guid<'m1>) : Guid<'m2> = Unsafe.cast x
+    static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : char<'m1>) : char<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : string<'m1>) : string<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : TimeSpan<'m1>) : TimeSpan<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : DateTime<'m1>) : DateTime<'m2> = Unsafe.cast x
@@ -85,6 +104,9 @@ type UMX =
 #if NET6_0_OR_GREATER
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : DateOnly<'m1>) : DateOnly<'m2> = Unsafe.cast x
     static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : TimeOnly<'m1>) : TimeOnly<'m2> = Unsafe.cast x
+    static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : uint<'m1>) : uint<'m2> = Unsafe.cast x
+#else
+    static member inline cast<[<Measure>]'m1, [<Measure>]'m2> (x : uint32<'m1>) : uint32<'m2> = Unsafe.cast x
 #endif
 
 
diff --git a/src/FSharp.UMX.fsproj b/src/FSharp.UMX.fsproj
index 07a6c1e..25c73a8 100644
--- a/src/FSharp.UMX.fsproj
+++ b/src/FSharp.UMX.fsproj
@@ -28,6 +28,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
-    <PackageReference Include="FSharp.Core" Version="4.3.4" />
+    <PackageReference Condition=" '$(TargetFramework)' == 'netstandard2.0' " Include="FSharp.Core" Version="4.3.4" />
+    <PackageReference Condition=" '$(TargetFramework)' == 'net6.0' " Include="FSharp.Core" Version="6.0.7" />
   </ItemGroup>
 </Project>
diff --git a/tests/FSharp.UMX.Tests.fs b/tests/FSharp.UMX.Tests.fs
index ea4fcfa..d558e4b 100644
--- a/tests/FSharp.UMX.Tests.fs
+++ b/tests/FSharp.UMX.Tests.fs
@@ -31,10 +31,17 @@ let ``Simple unit of measure conversions with cast operator``() =
     let x : Guid<skuId> = % Guid.NewGuid()
     let y : string<skuId> = % (%x).ToString()
     let z : int<km> = % 42
+    let uz : uint<km> = % 42u
+    let uz32 : uint32<km> = % 42u
+    let c : char<foo> = % 'c'
     let w : string<foo> = % sprintf "%O %s %d" %x %y %z
     let b : byte<foo> = % 1uy
+    let sb : sbyte<foo> = % 1y
     let s : int16<foo> = % 1s
-    let f : float32<foo>  = % 10.0f
+    let us : uint16<foo> = % 1us
+    let l : int64<km> = % 42L
+    let ul : uint64<km> = % 42UL
+    let f : float32<foo> = % 10.0f
     let d : DateTime<foo> = % DateTime.Now
     let don : DateOnly<foo> = % DateOnly.FromDateTime(DateTime.Now)
     let ton : TimeOnly<foo> = % TimeOnly.FromDateTime(DateTime.Now)
@@ -42,12 +49,18 @@ let ``Simple unit of measure conversions with cast operator``() =
 
 [<Fact>]
 let ``Simple unit of measure conversions with UMX.tag function``() =
-    let x = UMX.tag<skuId> (Guid.NewGuid())              
-    let y = UMX.tag<skuId> ((%x).ToString())             
-    let z = UMX.tag<km> (42)                          
-    let w = UMX.tag<foo> (sprintf "%O %s %d" %x %y %z) 
-    let b = UMX.tag<foo> (1uy)                         
-    let s = UMX.tag<foo> (1s)                         
+    let x = UMX.tag<skuId> (Guid.NewGuid())
+    let y = UMX.tag<skuId> ((%x).ToString())
+    let z = UMX.tag<km> (42)
+    let uz = UMX.tag<km> (42u)
+    let c = UMX.tag<km> ('c')
+    let w = UMX.tag<foo> (sprintf "%O %s %d" %x %y %z)
+    let b = UMX.tag<foo> (1uy)
+    let sb = UMX.tag<foo> (1y)
+    let s = UMX.tag<foo> (1s)
+    let us = UMX.tag<foo> (1us)
+    let l = UMX.tag<foo> (1l)
+    let ul = UMX.tag<foo> (1UL)
     let f = UMX.tag<foo> (10.0f)
     let d = UMX.tag<foo> DateTime.Now
     let don = UMX.tag<foo> (DateOnly.FromDateTime(DateTime.Now))