diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..9c297c3
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,3 @@
+## Unreleased version
+### Added
+* `Belt.Result.t` support
diff --git a/__tests__/test.re b/__tests__/test.re
index fa94675..d77d668 100644
--- a/__tests__/test.re
+++ b/__tests__/test.re
@@ -14,6 +14,7 @@ open Belt.Result; */
 [@decco] type a('a) = array('a);
 [@decco] type l('a) = list('a);
 [@decco] type o('a) = option('a);
+[@decco] type r('v, 'e) = Belt.Result.t('v, 'e);
 [@decco] type simpleVar('a) = 'a;
 [@decco] type j = Js.Json.t;
 [@decco] type optionList = l(o(s));
@@ -345,9 +346,9 @@ describe("option", () => {
     describe("o_encode", () => {
         test("none", () =>
             o_encode(s_encode, None)
-                |> Js.Json.classify
-                |> expect
-                |> toBe(Js.Json.JSONNull)
+            |> Js.Json.classify
+            |> expect
+            |> toBe(Js.Json.JSONNull)
         );
 
         test("some", () => {
@@ -374,6 +375,83 @@ describe("option", () => {
     });
 });
 
+describe("result", () => {
+    let enc = r_encode(s_encode, i_encode);
+    let dec = r_decode(s_decode, i_decode);
+
+    describe("r_encode", () => {
+        test("ok", () =>
+            Belt.Result.Ok("oaky")
+            |> enc
+            |> Js.Json.stringify
+            |> expect
+            |> toBe("[\"Ok\",\"oaky\"]")
+        );
+
+        test("error", () => {
+            Belt.Result.Error(404)
+            |> enc
+            |> Js.Json.stringify
+            |> expect
+            |> toBe("[\"Error\",404]")
+        });
+    });
+
+    describe("r_decode", () => {
+        describe("good", () => {
+            let json = "[\"Ok\",\"yess\"]" |> Js.Json.parseExn;
+            testGoodDecode("ok", dec, json, Ok("yess"));
+
+            let json = "[\"Error\",911]" |> Js.Json.parseExn;
+            testGoodDecode("error", dec, json, Error(911));
+        });
+
+        describe("bad", () => {
+            let json = Js.Json.number(12.);
+            testBadDecode("not an array", dec, json, {
+                path: "",
+                message: "Not an array",
+                value: json
+            });
+
+            let json = "[]" |> Js.Json.parseExn;
+            testBadDecode("length != 2", dec, json, {
+                path: "",
+                message: "Expected exactly 2 values in array",
+                value: json
+            });
+
+            let json = "[0,1]" |> Js.Json.parseExn;
+            testBadDecode("constructor not a string", dec, json, {
+                path: "",
+                message: "Not a string",
+                value: Js.Json.number(0.)
+            });
+
+            let json = "[\"bad\",1]" |> Js.Json.parseExn;
+            testBadDecode("unrecognized constructor", dec, json, {
+                path: "",
+                message: "Expected either \"Ok\" or \"Error\"",
+                value: Js.Json.string("bad")
+            });
+
+            let json = "[\"Ok\",1]" |> Js.Json.parseExn;
+            testBadDecode("bad Ok decode", dec, json, {
+                path: "",
+                message: "Not a string",
+                value: Js.Json.number(1.)
+            });
+
+            let json = "[\"Error\",null]" |> Js.Json.parseExn;
+            testBadDecode("bad Error decode", dec, json, {
+                path: "",
+                message: "Not a number",
+                value: Js.Json.null
+            });
+        });
+    });
+});
+
 describe("falseable", () => {
     describe("falseable_encode", () => {
         test("none", () =>
diff --git a/ppx/bin/Codecs.re b/ppx/bin/Codecs.re
index c8bca83..fdfad46 100644
--- a/ppx/bin/Codecs.re
+++ b/ppx/bin/Codecs.re
@@ -71,6 +71,10 @@ and generateConstrCodecs = ({ doEncode, doDecode }, { Location.txt: identifier,
             doEncode ? Some([%expr Decco.optionToJson]) : None,
             doDecode ? Some([%expr Decco.optionFromJson]) : None
         )
+        | Ldot(Ldot(Lident("Belt"), "Result"), "t") => (
+            doEncode ? Some([%expr Decco.resultToJson]) : None,
+            doDecode ? Some([%expr Decco.resultFromJson]) : None
+        )
         | Ldot(Ldot(Lident("Js"), "Json"), "t") => (
             doEncode ? Some([%expr (v) => v]) : None,
             doDecode ? Some([%expr (v) => Belt.Result.Ok(v)]) : None,
diff --git a/src/Decco.re b/src/Decco.re
index d4c2743..d892b54 100644
--- a/src/Decco.re
+++ b/src/Decco.re
@@ -119,6 +119,34 @@ let optionFromJson = (decoder, json) =>
         | _ => decoder(json) |> map(_, v => Some(v))
     };
 
+let resultToJson = (okEncoder, errorEncoder, result) =>
+    switch result {
+        | Ok(v) => [| Js.Json.string("Ok"), okEncoder(v) |]
+        | Error(e) => [| Js.Json.string("Error"), errorEncoder(e) |]
+    }
+    |> Js.Json.array;
+
+let resultFromJson = (okDecoder, errorDecoder, json) =>
+    switch (Js.Json.decodeArray(json)) {
+        | Some([| variantConstructorId, payload |]) =>
+            switch (Js.Json.decodeString(variantConstructorId)) {
+                | Some("Ok") =>
+                    okDecoder(payload)
+                    -> Belt.Result.map(v => Ok(v))
+
+                | Some("Error") =>
+                    switch(errorDecoder(payload)) {
+                        | Ok(v) => Ok(Error(v))
+                        | Error(e) => Error(e)
+                    }
+
+                | Some(_) => error("Expected either \"Ok\" or \"Error\"", variantConstructorId)
+                | None => error("Not a string", variantConstructorId)
+            }
+        | Some(_) => error("Expected exactly 2 values in array", json)
+        | None => error("Not an array", json)
+    };
+
 module Codecs {
     include Codecs;
     let string = (stringToJson, stringFromJson);