diff --git a/CHANGELOG.md b/CHANGELOG.md
index b3272d4ce0..44059a7f9a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,8 @@
 
 #### :rocket: New Feature
 
+- Add support for Set, Map, WeakSet and WeakMap to `@unboxed`. https://github.com/rescript-lang/rescript/pull/8009
+
 #### :bug: Bug fix
 
 - Fix fatal compiler error that occurred when an `%ffi` extension point contained invalid JavaScript https://github.com/rescript-lang/rescript/pull/7998
diff --git a/compiler/ml/ast_untagged_variants.ml b/compiler/ml/ast_untagged_variants.ml
index 9cb7d015c8..06673db5ed 100644
--- a/compiler/ml/ast_untagged_variants.ml
+++ b/compiler/ml/ast_untagged_variants.ml
@@ -19,6 +19,10 @@ module Instance = struct
     | Uint32Array
     | Uint8Array
     | Uint8ClampedArray
+    | Set
+    | Map
+    | WeakSet
+    | WeakMap
   let to_string = function
     | Array -> "Array"
     | ArrayBuffer -> "ArrayBuffer"
@@ -39,6 +43,10 @@ module Instance = struct
     | Uint32Array -> "Uint32Array"
     | Uint8Array -> "Uint8Array"
     | Uint8ClampedArray -> "Uint8ClampedArray"
+    | Set -> "Set"
+    | Map -> "Map"
+    | WeakSet -> "WeakSet"
+    | WeakMap -> "WeakMap"
 end
 
 type untagged_error =
@@ -256,6 +264,10 @@ let type_to_instanceof_backed_obj (t : Types.type_expr) =
     | "Stdlib.Uint8ClampedArray.t" -> Some Uint8ClampedArray
     | "Js_file.t" -> Some File
     | "Js_blob.t" -> Some Blob
+    | "Stdlib.Set.t" -> Some Set
+    | "Stdlib.Map.t" -> Some Map
+    | "Stdlib.WeakSet.t" -> Some WeakSet
+    | "Stdlib.WeakMap.t" -> Some WeakMap
     | _ -> None)
   | _ -> None
 
diff --git a/tests/tests/src/UntaggedVariants.mjs b/tests/tests/src/UntaggedVariants.mjs
index b5384b39ec..29e4477626 100644
--- a/tests/tests/src/UntaggedVariants.mjs
+++ b/tests/tests/src/UntaggedVariants.mjs
@@ -573,6 +573,22 @@ async function classifyAll(t) {
     console.log("DataView");
     return;
   }
+  if (t instanceof Set) {
+    console.log("Set");
+    return;
+  }
+  if (t instanceof Map) {
+    console.log("Map");
+    return;
+  }
+  if (t instanceof WeakSet) {
+    console.log("WeakSet");
+    return;
+  }
+  if (t instanceof WeakMap) {
+    console.log("WeakMap");
+    return;
+  }
   switch (typeof t) {
     case "string" :
       console.log(t);
diff --git a/tests/tests/src/UntaggedVariants.res b/tests/tests/src/UntaggedVariants.res
index 8b55e268a4..9ec7aa0d92 100644
--- a/tests/tests/src/UntaggedVariants.res
+++ b/tests/tests/src/UntaggedVariants.res
@@ -413,6 +413,10 @@ module AllInstanceofTypes = {
     | BigInt64Array(BigInt64Array.t)
     | BigUint64Array(BigUint64Array.t)
     | DataView(DataView.t)
+    | Set(Set.t<string>)
+    | Map(Map.t<string, unknown>)
+    | WeakSet(WeakSet.t<string>)
+    | WeakMap(WeakMap.t<string, unknown>)
 
   let classifyAll = async (t: t) =>
     switch t {
@@ -437,6 +441,10 @@ module AllInstanceofTypes = {
     | BigInt64Array(_) => Console.log("BigInt64Array")
     | BigUint64Array(_) => Console.log("BigUint64Array")
     | DataView(_) => Console.log("DataView")
+    | Set(_) => Console.log("Set")
+    | Map(_) => Console.log("Map")
+    | WeakSet(_) => Console.log("WeakSet")
+    | WeakMap(_) => Console.log("WeakMap")
     }
 }