diff --git a/packages/Thoth.Json.Core/CHANGELOG.md b/packages/Thoth.Json.Core/CHANGELOG.md
index d28f294..06b35a5 100644
--- a/packages/Thoth.Json.Core/CHANGELOG.md
+++ b/packages/Thoth.Json.Core/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 * Add `resizeArray` support ([GH-182](https://github.com/thoth-org/Thoth.Json/issues/182))
+* Add `IEncoderHelpers.encodeResizeArray` ([GH-199](https://github.com/thoth-org/Thoth.Json/issues/199))
 
 ### Changed
 
diff --git a/packages/Thoth.Json.Core/Encode.fs b/packages/Thoth.Json.Core/Encode.fs
index cea7965..77e89a1 100644
--- a/packages/Thoth.Json.Core/Encode.fs
+++ b/packages/Thoth.Json.Core/Encode.fs
@@ -74,9 +74,12 @@ module Encode =
     let resizeArray (values: IEncodable ResizeArray) =
         { new IEncodable with
             member _.Encode(helpers) =
-                values
-                |> Seq.map (fun v -> v.Encode(helpers))
-                |> helpers.encodeSeq
+                let result = ResizeArray(values.Count)
+
+                for v in values do
+                    result.Add(v.Encode(helpers))
+
+                helpers.encodeResizeArray result
         }
 
     let dict (values: Map<string, IEncodable>) : IEncodable =
diff --git a/packages/Thoth.Json.Core/Types.fs b/packages/Thoth.Json.Core/Types.fs
index 776d321..e670c7a 100644
--- a/packages/Thoth.Json.Core/Types.fs
+++ b/packages/Thoth.Json.Core/Types.fs
@@ -29,6 +29,7 @@ type IEncoderHelpers<'JsonValue> =
     abstract encodeArray: 'JsonValue array -> 'JsonValue
     abstract encodeList: 'JsonValue list -> 'JsonValue
     abstract encodeSeq: 'JsonValue seq -> 'JsonValue
+    abstract encodeResizeArray: ResizeArray<'JsonValue> -> 'JsonValue
     // See https://github.com/thoth-org/Thoth.Json/issues/187 for more information
     // about why we make a distinction between signed and unsigned integral numbers
     // when encoding them.
diff --git a/packages/Thoth.Json.JavaScript/Encode.fs b/packages/Thoth.Json.JavaScript/Encode.fs
index d58f56a..65d8ce7 100644
--- a/packages/Thoth.Json.JavaScript/Encode.fs
+++ b/packages/Thoth.Json.JavaScript/Encode.fs
@@ -28,6 +28,9 @@ module Encode =
             member _.encodeList values = JS.Constructors.Array.from values
             member _.encodeSeq values = JS.Constructors.Array.from values
 
+            member _.encodeResizeArray values =
+                JS.Constructors.Array.from values
+
             member _.encodeSignedIntegralNumber value = box value
             member _.encodeUnsignedIntegralNumber value = box value
         }
diff --git a/packages/Thoth.Json.Newtonsoft/Encode.fs b/packages/Thoth.Json.Newtonsoft/Encode.fs
index bbfd1e8..3415e91 100644
--- a/packages/Thoth.Json.Newtonsoft/Encode.fs
+++ b/packages/Thoth.Json.Newtonsoft/Encode.fs
@@ -27,6 +27,7 @@ module Encode =
             member _.encodeArray values = JArray(values)
             member _.encodeList values = JArray(values)
             member _.encodeSeq values = JArray(values)
+            member _.encodeResizeArray values = JArray(values)
 
             member _.encodeSignedIntegralNumber(value: int32) = JValue(value)
 
diff --git a/packages/Thoth.Json.Python/Encode.fs b/packages/Thoth.Json.Python/Encode.fs
index 6006ea4..899f44e 100644
--- a/packages/Thoth.Json.Python/Encode.fs
+++ b/packages/Thoth.Json.Python/Encode.fs
@@ -32,6 +32,9 @@ module Encode =
             member this.encodeSeq values =
                 values |> Seq.toArray |> this.encodeArray
 
+            member this.encodeResizeArray values =
+                values.ToArray() |> this.encodeArray
+
             member _.encodeSignedIntegralNumber value = box value
             member _.encodeUnsignedIntegralNumber value = box value
         }