diff --git a/src/fable-library-py/fable_library/System.Text.fs b/src/fable-library-py/fable_library/System.Text.fs
index 1fa48be009..debe8a2cf1 100644
--- a/src/fable-library-py/fable_library/System.Text.fs
+++ b/src/fable-library-py/fable_library/System.Text.fs
@@ -31,10 +31,42 @@ type StringBuilder(value: string, capacity: int) =
         buf.Add(s)
         x
 
+    member x.Append(o: int8) =
+        buf.Add(string<int8> o)
+        x
+
+    member x.Append(o: byte) =
+        buf.Add(string<byte> o)
+        x
+
+    member x.Append(o: int16) =
+        buf.Add(string<int16> o)
+        x
+
+    member x.Append(o: uint16) =
+        buf.Add(string<uint16> o)
+        x
+
     member x.Append(o: int) =
         buf.Add(string<int> o)
         x
 
+    member x.Append(o: uint32) =
+        buf.Add(string<uint32> o)
+        x
+
+    member x.Append(o: int64) =
+        buf.Add(string<int64> o)
+        x
+
+    member x.Append(o: uint64) =
+        buf.Add(string<uint64> o)
+        x
+
+    member x.Append(o: float32) =
+        buf.Add(string<float32> o)
+        x
+
     member x.Append(o: float) =
         buf.Add(string<float> o)
         x
diff --git a/src/fable-library-ts/System.Text.fs b/src/fable-library-ts/System.Text.fs
index fd1b6f47ea..685cc1df3d 100644
--- a/src/fable-library-ts/System.Text.fs
+++ b/src/fable-library-ts/System.Text.fs
@@ -28,10 +28,42 @@ type StringBuilder(value: string, capacity: int) =
         buf.Add(s)
         x
 
+    member x.Append(o: int8) =
+        buf.Add(string<int8> o)
+        x
+
+    member x.Append(o: byte) =
+        buf.Add(string<byte> o)
+        x
+
+    member x.Append(o: int16) =
+        buf.Add(string<int16> o)
+        x
+
+    member x.Append(o: uint16) =
+        buf.Add(string<uint16> o)
+        x
+
     member x.Append(o: int) =
         buf.Add(string<int> o)
         x
 
+    member x.Append(o: uint32) =
+        buf.Add(string<uint32> o)
+        x
+
+    member x.Append(o: int64) =
+        buf.Add(string<int64> o)
+        x
+
+    member x.Append(o: uint64) =
+        buf.Add(string<uint64> o)
+        x
+
+    member x.Append(o: float32) =
+        buf.Add(string<float32> o)
+        x
+
     member x.Append(o: float) =
         buf.Add(string<float> o)
         x
diff --git a/tests/Js/Main/StringTests.fs b/tests/Js/Main/StringTests.fs
index 8f430baf86..220c747093 100644
--- a/tests/Js/Main/StringTests.fs
+++ b/tests/Js/Main/StringTests.fs
@@ -110,6 +110,18 @@ let tests = testList "Strings" [
         let actual = sb.ToString().Replace(",", ".").ToLower()
         actual |> equal "aaabcd/true5.234xxxx"
 
+    testCase "StringBuilder.Append works with numeric type overloads" <| fun () ->
+        let sb = System.Text.StringBuilder()
+        sb.Append(1y) |> ignore   // int8
+        sb.Append(2uy) |> ignore  // byte
+        sb.Append(3s) |> ignore   // int16
+        sb.Append(4us) |> ignore  // uint16
+        sb.Append(5u) |> ignore   // uint32
+        sb.Append(6L) |> ignore   // int64
+        sb.Append(7UL) |> ignore  // uint64
+        sb.Append(8.0f) |> ignore // float32
+        sb.ToString().Replace(",", ".") |> equal "12345678"
+
     testCase "StringBuilder.AppendFormat works" <| fun () ->
         let sb = System.Text.StringBuilder()
         sb.AppendFormat("Hello{0}World{1}", " ", "!") |> ignore
diff --git a/tests/Python/TestString.fs b/tests/Python/TestString.fs
index 65a4cb0139..d24644b914 100644
--- a/tests/Python/TestString.fs
+++ b/tests/Python/TestString.fs
@@ -261,6 +261,19 @@ let ``test StringBuilder.Append works with various overloads`` () =
     let actual = sb.ToString().ToLower()
     actual |> equal "aaabcd/true5.234xxxx"
 
+[<Fact>]
+let ``test StringBuilder.Append works with numeric type overloads`` () =
+    let sb = System.Text.StringBuilder()
+    sb.Append(1y) |> ignore   // int8
+    sb.Append(2uy) |> ignore  // byte
+    sb.Append(3s) |> ignore   // int16
+    sb.Append(4us) |> ignore  // uint16
+    sb.Append(5u) |> ignore   // uint32
+    sb.Append(6L) |> ignore   // int64
+    sb.Append(7UL) |> ignore  // uint64
+    sb.Append(8.0f) |> ignore // float32
+    sb.ToString() |> equal "12345678"
+
 [<Fact>]
 let ``test StringBuilder.AppendFormat works`` () =
     let sb = System.Text.StringBuilder()