diff --git a/src/Core__Option.mjs b/src/Core__Option.mjs
index 776bc0bf..52379716 100644
--- a/src/Core__Option.mjs
+++ b/src/Core__Option.mjs
@@ -98,6 +98,107 @@ function compare(a, b, cmp) {
   }
 }
 
+function all(options) {
+  var acc = [];
+  var returnValue;
+  var index = 0;
+  while(returnValue === undefined && index < options.length) {
+    var value = options[index];
+    if (value !== undefined) {
+      acc.push(Caml_option.valFromOption(value));
+      index = index + 1 | 0;
+    } else {
+      returnValue = Caml_option.some(undefined);
+    }
+  };
+  var match = returnValue;
+  if (match !== undefined) {
+    return ;
+  } else {
+    return acc;
+  }
+}
+
+function all2(param) {
+  var b = param[1];
+  var a = param[0];
+  if (a !== undefined && b !== undefined) {
+    return [
+            Caml_option.valFromOption(a),
+            Caml_option.valFromOption(b)
+          ];
+  }
+  
+}
+
+function all3(param) {
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a !== undefined && b !== undefined && c !== undefined) {
+    return [
+            Caml_option.valFromOption(a),
+            Caml_option.valFromOption(b),
+            Caml_option.valFromOption(c)
+          ];
+  }
+  
+}
+
+function all4(param) {
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a !== undefined && b !== undefined && c !== undefined && d !== undefined) {
+    return [
+            Caml_option.valFromOption(a),
+            Caml_option.valFromOption(b),
+            Caml_option.valFromOption(c),
+            Caml_option.valFromOption(d)
+          ];
+  }
+  
+}
+
+function all5(param) {
+  var e = param[4];
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a !== undefined && b !== undefined && c !== undefined && d !== undefined && e !== undefined) {
+    return [
+            Caml_option.valFromOption(a),
+            Caml_option.valFromOption(b),
+            Caml_option.valFromOption(c),
+            Caml_option.valFromOption(d),
+            Caml_option.valFromOption(e)
+          ];
+  }
+  
+}
+
+function all6(param) {
+  var f = param[5];
+  var e = param[4];
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a !== undefined && b !== undefined && c !== undefined && d !== undefined && e !== undefined && f !== undefined) {
+    return [
+            Caml_option.valFromOption(a),
+            Caml_option.valFromOption(b),
+            Caml_option.valFromOption(c),
+            Caml_option.valFromOption(d),
+            Caml_option.valFromOption(e),
+            Caml_option.valFromOption(f)
+          ];
+  }
+  
+}
+
 var mapWithDefault = mapOr;
 
 var getWithDefault = getOr;
@@ -117,5 +218,11 @@ export {
   isNone ,
   equal ,
   compare ,
+  all ,
+  all2 ,
+  all3 ,
+  all4 ,
+  all5 ,
+  all6 ,
 }
 /* No side effect */
diff --git a/src/Core__Option.res b/src/Core__Option.res
index a799a0ea..843bd511 100644
--- a/src/Core__Option.res
+++ b/src/Core__Option.res
@@ -98,3 +98,56 @@ let compare = (a, b, cmp) =>
   | (Some(_), None) => Core__Ordering.greater
   | (None, None) => Core__Ordering.equal
   }
+
+let all = options => {
+  let acc = []
+  let returnValue = ref(None)
+  let index = ref(0)
+  while returnValue.contents == None && index.contents < options->Core__Array.length {
+    switch options->Core__Array.getUnsafe(index.contents) {
+    | None => returnValue.contents = Some(None)
+    | Some(value) =>
+      acc->Core__Array.push(value)
+      index.contents = index.contents + 1
+    }
+  }
+  switch returnValue.contents {
+  | Some(_) => None
+  | None => Some(acc)
+  }
+}
+
+let all2 = ((a, b)) => {
+  switch (a, b) {
+  | (Some(a), Some(b)) => Some((a, b))
+  | _ => None
+  }
+}
+
+let all3 = ((a, b, c)) => {
+  switch (a, b, c) {
+  | (Some(a), Some(b), Some(c)) => Some((a, b, c))
+  | _ => None
+  }
+}
+
+let all4 = ((a, b, c, d)) => {
+  switch (a, b, c, d) {
+  | (Some(a), Some(b), Some(c), Some(d)) => Some((a, b, c, d))
+  | _ => None
+  }
+}
+
+let all5 = ((a, b, c, d, e)) => {
+  switch (a, b, c, d, e) {
+  | (Some(a), Some(b), Some(c), Some(d), Some(e)) => Some((a, b, c, d, e))
+  | _ => None
+  }
+}
+
+let all6 = ((a, b, c, d, e, f)) => {
+  switch (a, b, c, d, e, f) {
+  | (Some(a), Some(b), Some(c), Some(d), Some(e), Some(f)) => Some((a, b, c, d, e, f))
+  | _ => None
+  }
+}
diff --git a/src/Core__Option.resi b/src/Core__Option.resi
index fbaceba4..cc97a652 100644
--- a/src/Core__Option.resi
+++ b/src/Core__Option.resi
@@ -252,3 +252,53 @@ Option.compare(None, None, clockCompare) // 0.
 ```
 */
 let compare: (option<'a>, option<'b>, ('a, 'b) => Core__Ordering.t) => Core__Ordering.t
+
+/**
+`all(options)` returns an option of array if all options are Some, otherwise returns None.
+
+## Examples
+
+```rescript
+Option.all([Some(1), Some(2), Some(3)]) // Some([1, 2, 3])
+Option.all([Some(1), None]) // None
+```
+*/
+let all: array<option<'a>> => option<array<'a>>
+
+/**
+`all2((o1, o2))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all2: ((option<'a>, option<'b>)) => option<('a, 'b)>
+
+/**
+`all3((o1, o2, o3))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all3: ((option<'a>, option<'b>, option<'c>)) => option<('a, 'b, 'c)>
+
+/**
+`all4((o1, o2, o3, o4))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all4: ((option<'a>, option<'b>, option<'c>, option<'d>)) => option<('a, 'b, 'c, 'd)>
+
+/**
+`all5((o1, o2, o3, o4, o5))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all5: ((option<'a>, option<'b>, option<'c>, option<'d>, option<'e>)) => option<(
+  'a,
+  'b,
+  'c,
+  'd,
+  'e,
+)>
+
+/**
+`all6((o1, o2, o3, o4, o5, o6))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all6: ((option<'a>, option<'b>, option<'c>, option<'d>, option<'e>, option<'f>)) => option<(
+  'a,
+  'b,
+  'c,
+  'd,
+  'e,
+  'f,
+)>
diff --git a/src/Core__Result.mjs b/src/Core__Result.mjs
index 6ec9cb05..229517dd 100644
--- a/src/Core__Result.mjs
+++ b/src/Core__Result.mjs
@@ -108,6 +108,250 @@ function mapError(r, f) {
   }
 }
 
+function all(results) {
+  var acc = [];
+  var returnValue;
+  var index = 0;
+  while(returnValue === undefined && index < results.length) {
+    var err = results[index];
+    if (err.TAG === "Ok") {
+      acc.push(err._0);
+      index = index + 1 | 0;
+    } else {
+      returnValue = err;
+    }
+  };
+  var error = returnValue;
+  if (error !== undefined) {
+    return error;
+  } else {
+    return {
+            TAG: "Ok",
+            _0: acc
+          };
+  }
+}
+
+function all2(param) {
+  var b = param[1];
+  var a = param[0];
+  if (a.TAG === "Ok") {
+    if (b.TAG === "Ok") {
+      return {
+              TAG: "Ok",
+              _0: [
+                a._0,
+                b._0
+              ]
+            };
+    } else {
+      return {
+              TAG: "Error",
+              _0: b._0
+            };
+    }
+  } else {
+    return {
+            TAG: "Error",
+            _0: a._0
+          };
+  }
+}
+
+function all3(param) {
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a.TAG === "Ok") {
+    if (b.TAG === "Ok") {
+      if (c.TAG === "Ok") {
+        return {
+                TAG: "Ok",
+                _0: [
+                  a._0,
+                  b._0,
+                  c._0
+                ]
+              };
+      } else {
+        return {
+                TAG: "Error",
+                _0: c._0
+              };
+      }
+    } else {
+      return {
+              TAG: "Error",
+              _0: b._0
+            };
+    }
+  } else {
+    return {
+            TAG: "Error",
+            _0: a._0
+          };
+  }
+}
+
+function all4(param) {
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a.TAG === "Ok") {
+    if (b.TAG === "Ok") {
+      if (c.TAG === "Ok") {
+        if (d.TAG === "Ok") {
+          return {
+                  TAG: "Ok",
+                  _0: [
+                    a._0,
+                    b._0,
+                    c._0,
+                    d._0
+                  ]
+                };
+        } else {
+          return {
+                  TAG: "Error",
+                  _0: d._0
+                };
+        }
+      } else {
+        return {
+                TAG: "Error",
+                _0: c._0
+              };
+      }
+    } else {
+      return {
+              TAG: "Error",
+              _0: b._0
+            };
+    }
+  } else {
+    return {
+            TAG: "Error",
+            _0: a._0
+          };
+  }
+}
+
+function all5(param) {
+  var e = param[4];
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a.TAG === "Ok") {
+    if (b.TAG === "Ok") {
+      if (c.TAG === "Ok") {
+        if (d.TAG === "Ok") {
+          if (e.TAG === "Ok") {
+            return {
+                    TAG: "Ok",
+                    _0: [
+                      a._0,
+                      b._0,
+                      c._0,
+                      d._0,
+                      e._0
+                    ]
+                  };
+          } else {
+            return {
+                    TAG: "Error",
+                    _0: e._0
+                  };
+          }
+        } else {
+          return {
+                  TAG: "Error",
+                  _0: d._0
+                };
+        }
+      } else {
+        return {
+                TAG: "Error",
+                _0: c._0
+              };
+      }
+    } else {
+      return {
+              TAG: "Error",
+              _0: b._0
+            };
+    }
+  } else {
+    return {
+            TAG: "Error",
+            _0: a._0
+          };
+  }
+}
+
+function all6(param) {
+  var f = param[5];
+  var e = param[4];
+  var d = param[3];
+  var c = param[2];
+  var b = param[1];
+  var a = param[0];
+  if (a.TAG === "Ok") {
+    if (b.TAG === "Ok") {
+      if (c.TAG === "Ok") {
+        if (d.TAG === "Ok") {
+          if (e.TAG === "Ok") {
+            if (f.TAG === "Ok") {
+              return {
+                      TAG: "Ok",
+                      _0: [
+                        a._0,
+                        b._0,
+                        c._0,
+                        d._0,
+                        e._0,
+                        f._0
+                      ]
+                    };
+            } else {
+              return {
+                      TAG: "Error",
+                      _0: f._0
+                    };
+            }
+          } else {
+            return {
+                    TAG: "Error",
+                    _0: e._0
+                  };
+          }
+        } else {
+          return {
+                  TAG: "Error",
+                  _0: d._0
+                };
+        }
+      } else {
+        return {
+                TAG: "Error",
+                _0: c._0
+              };
+      }
+    } else {
+      return {
+              TAG: "Error",
+              _0: b._0
+            };
+    }
+  } else {
+    return {
+            TAG: "Error",
+            _0: a._0
+          };
+  }
+}
+
 var mapWithDefault = mapOr;
 
 var getWithDefault = getOr;
@@ -126,5 +370,11 @@ export {
   compare ,
   forEach ,
   mapError ,
+  all ,
+  all2 ,
+  all3 ,
+  all4 ,
+  all5 ,
+  all6 ,
 }
 /* No side effect */
diff --git a/src/Core__Result.res b/src/Core__Result.res
index a2abc3d0..dbbf0709 100644
--- a/src/Core__Result.res
+++ b/src/Core__Result.res
@@ -95,3 +95,71 @@ let mapError = (r, f) =>
   | Ok(_) as result => result
   | Error(e) => Error(f(e))
   }
+
+let all = results => {
+  let acc = []
+  let returnValue = ref(None)
+  let index = ref(0)
+  while returnValue.contents == None && index.contents < results->Core__Array.length {
+    switch results->Core__Array.getUnsafe(index.contents) {
+    | Error(_) as err => returnValue.contents = Some(err)
+    | Ok(value) =>
+      acc->Core__Array.push(value)
+      index.contents = index.contents + 1
+    }
+  }
+  switch returnValue.contents {
+  | Some(error) => error
+  | None => Ok(acc)
+  }
+}
+
+let all2 = ((a, b)) => {
+  switch (a, b) {
+  | (Ok(a), Ok(b)) => Ok((a, b))
+  | (Error(a), _) => Error(a)
+  | (_, Error(b)) => Error(b)
+  }
+}
+
+let all3 = ((a, b, c)) => {
+  switch (a, b, c) {
+  | (Ok(a), Ok(b), Ok(c)) => Ok((a, b, c))
+  | (Error(a), _, _) => Error(a)
+  | (_, Error(b), _) => Error(b)
+  | (_, _, Error(c)) => Error(c)
+  }
+}
+
+let all4 = ((a, b, c, d)) => {
+  switch (a, b, c, d) {
+  | (Ok(a), Ok(b), Ok(c), Ok(d)) => Ok((a, b, c, d))
+  | (Error(a), _, _, _) => Error(a)
+  | (_, Error(b), _, _) => Error(b)
+  | (_, _, Error(c), _) => Error(c)
+  | (_, _, _, Error(d)) => Error(d)
+  }
+}
+
+let all5 = ((a, b, c, d, e)) => {
+  switch (a, b, c, d, e) {
+  | (Ok(a), Ok(b), Ok(c), Ok(d), Ok(e)) => Ok((a, b, c, d, e))
+  | (Error(a), _, _, _, _) => Error(a)
+  | (_, Error(b), _, _, _) => Error(b)
+  | (_, _, Error(c), _, _) => Error(c)
+  | (_, _, _, Error(d), _) => Error(d)
+  | (_, _, _, _, Error(e)) => Error(e)
+  }
+}
+
+let all6 = ((a, b, c, d, e, f)) => {
+  switch (a, b, c, d, e, f) {
+  | (Ok(a), Ok(b), Ok(c), Ok(d), Ok(e), Ok(f)) => Ok((a, b, c, d, e, f))
+  | (Error(a), _, _, _, _, _) => Error(a)
+  | (_, Error(b), _, _, _, _) => Error(b)
+  | (_, _, Error(c), _, _, _) => Error(c)
+  | (_, _, _, Error(d), _, _) => Error(d)
+  | (_, _, _, _, Error(e), _) => Error(e)
+  | (_, _, _, _, _, Error(f)) => Error(f)
+  }
+}
diff --git a/src/Core__Result.resi b/src/Core__Result.resi
index a30c5e0b..2deba928 100644
--- a/src/Core__Result.resi
+++ b/src/Core__Result.resi
@@ -234,3 +234,54 @@ Result.mapError(Ok("abc"), format) // Ok("abc")
 ```
 */
 let mapError: (result<'a, 'b>, 'b => 'c) => result<'a, 'c>
+
+/**
+`all(results)` returns a result of array if all options are Ok, otherwise returns Error.
+
+## Examples
+
+```rescript
+Result.all([Ok(1), Ok(2), Ok(3)]) // Ok([1, 2, 3])
+Result.all([Ok(1), Error(1)]) // Error(1)
+```
+*/
+let all: array<result<'a, 'b>> => result<array<'a>, 'b>
+
+/**
+`all2((r1, r2))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all2: ((result<'r1, 'e>, result<'r2, 'e>)) => result<('r1, 'r2), 'e>
+
+/**
+`all3((r1, r2, r3))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all3: ((result<'r1, 'e>, result<'r2, 'e>, result<'r3, 'e>)) => result<('r1, 'r2, 'r3), 'e>
+
+/**
+`all4((r1, r2, r3, r4))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all4: ((result<'r1, 'e>, result<'r2, 'e>, result<'r3, 'e>, result<'r4, 'e>)) => result<
+  ('r1, 'r2, 'r3, 'r4),
+  'e,
+>
+
+/**
+`all5((r1, r2, r3, r4, r5))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all5: (
+  (result<'r1, 'e>, result<'r2, 'e>, result<'r3, 'e>, result<'r4, 'e>, result<'r5, 'e>)
+) => result<('r1, 'r2, 'r3, 'r4, 'r5), 'e>
+
+/**
+`all6((r1, r2, r3, r4, r5, r6))`. Like `all()`, but with a fixed size tuple of 2
+*/
+let all6: (
+  (
+    result<'r1, 'e>,
+    result<'r2, 'e>,
+    result<'r3, 'e>,
+    result<'r4, 'e>,
+    result<'r5, 'e>,
+    result<'r6, 'e>,
+  )
+) => result<('r1, 'r2, 'r3, 'r4, 'r5, 'r6), 'e>
diff --git a/test/OptionTests.mjs b/test/OptionTests.mjs
new file mode 100644
index 00000000..dc8ea16b
--- /dev/null
+++ b/test/OptionTests.mjs
@@ -0,0 +1,53 @@
+// Generated by ReScript, PLEASE EDIT WITH CARE
+
+import * as Test from "./Test.mjs";
+import * as Caml_obj from "rescript/lib/es6/caml_obj.js";
+import * as Core__Option from "../src/Core__Option.mjs";
+
+var eq = Caml_obj.equal;
+
+Test.run([
+      [
+        "OptionTests.res",
+        5,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Option.all([]), eq, []);
+
+Test.run([
+      [
+        "OptionTests.res",
+        6,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Option.all([
+          1,
+          2,
+          3
+        ]), eq, [
+      1,
+      2,
+      3
+    ]);
+
+Test.run([
+      [
+        "OptionTests.res",
+        7,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Option.all([
+          1,
+          undefined
+        ]), eq, undefined);
+
+export {
+  eq ,
+}
+/*  Not a pure module */
diff --git a/test/OptionTests.res b/test/OptionTests.res
new file mode 100644
index 00000000..7461b84f
--- /dev/null
+++ b/test/OptionTests.res
@@ -0,0 +1,7 @@
+open RescriptCore
+
+let eq = (a, b) => a == b
+
+Test.run(__POS_OF__("all"), Option.all([]), eq, Some([]))
+Test.run(__POS_OF__("all"), Option.all([Some(1), Some(2), Some(3)]), eq, Some([1, 2, 3]))
+Test.run(__POS_OF__("all"), Option.all([Some(1), None]), eq, None)
diff --git a/test/ResultTests.mjs b/test/ResultTests.mjs
index a191b784..9d7d0023 100644
--- a/test/ResultTests.mjs
+++ b/test/ResultTests.mjs
@@ -88,6 +88,71 @@ Test.run([
       _0: 15
     });
 
+Test.run([
+      [
+        "ResultTests.res",
+        36,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Result.all([]), eq, {
+      TAG: "Ok",
+      _0: []
+    });
+
+Test.run([
+      [
+        "ResultTests.res",
+        37,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Result.all([
+          {
+            TAG: "Ok",
+            _0: 1
+          },
+          {
+            TAG: "Ok",
+            _0: 2
+          },
+          {
+            TAG: "Ok",
+            _0: 3
+          }
+        ]), eq, {
+      TAG: "Ok",
+      _0: [
+        1,
+        2,
+        3
+      ]
+    });
+
+Test.run([
+      [
+        "ResultTests.res",
+        38,
+        20,
+        25
+      ],
+      "all"
+    ], Core__Result.all([
+          {
+            TAG: "Ok",
+            _0: 1
+          },
+          {
+            TAG: "Error",
+            _0: 2
+          }
+        ]), eq, {
+      TAG: "Error",
+      _0: 2
+    });
+
 export {
   eq ,
   forEachIfOkCallFunction ,
diff --git a/test/ResultTests.res b/test/ResultTests.res
index 040028c6..6aa070ec 100644
--- a/test/ResultTests.res
+++ b/test/ResultTests.res
@@ -32,3 +32,7 @@ Test.run(
   eq,
   Error(15),
 )
+
+Test.run(__POS_OF__("all"), Result.all([]), eq, Ok([]))
+Test.run(__POS_OF__("all"), Result.all([Ok(1), Ok(2), Ok(3)]), eq, Ok([1, 2, 3]))
+Test.run(__POS_OF__("all"), Result.all([Ok(1), Error(2)]), eq, Error(2))
diff --git a/test/intl/Intl__CollatorTest.mjs b/test/intl/Intl__CollatorTest.mjs
index a42c8e08..bbff943d 100644
--- a/test/intl/Intl__CollatorTest.mjs
+++ b/test/intl/Intl__CollatorTest.mjs
@@ -5,14 +5,14 @@ console.log("---");
 
 console.log("Intl.Collator");
 
-new Intl.Collator(undefined, undefined);
+new Intl.Collator();
 
-new Intl.Collator(["en-US"], undefined);
+new Intl.Collator(["en-US"]);
 
 var _collator = new Intl.Collator([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 var collator = new Intl.Collator(["en-US"], {
       sensitivity: "base",
@@ -24,7 +24,7 @@ var collator = new Intl.Collator(["en-US"], {
 Intl.Collator.supportedLocalesOf([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 Intl.Collator.supportedLocalesOf([
       "en-US",
@@ -37,7 +37,7 @@ console.log(collator.resolvedOptions());
 
 console.log(collator.compare("hi", "hï"));
 
-console.log(Intl.Collator.supportedLocalesOf(["hi"], undefined));
+console.log(Intl.Collator.supportedLocalesOf(["hi"]));
 
 export {
   _collator ,
diff --git a/test/intl/Intl__DateTimeFormatTest.mjs b/test/intl/Intl__DateTimeFormatTest.mjs
index 62e31e91..140ae17c 100644
--- a/test/intl/Intl__DateTimeFormatTest.mjs
+++ b/test/intl/Intl__DateTimeFormatTest.mjs
@@ -9,7 +9,7 @@ console.log("Intl.DateTimeFormat");
 Intl.DateTimeFormat.supportedLocalesOf([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 Intl.DateTimeFormat.supportedLocalesOf([
       "en-US",
@@ -77,7 +77,7 @@ var formatter$6 = new Intl.DateTimeFormat(undefined, (newrecord$4.timeZoneName =
 
 console.log(formatter$6.format(new Date(Date.now())));
 
-var resolvedOptions = new Intl.DateTimeFormat(undefined, undefined).resolvedOptions();
+var resolvedOptions = new Intl.DateTimeFormat().resolvedOptions();
 
 var timeZone = resolvedOptions.timeZone;
 
diff --git a/test/intl/Intl__ListFormatTest.mjs b/test/intl/Intl__ListFormatTest.mjs
index f4bb15e8..32cc1d48 100644
--- a/test/intl/Intl__ListFormatTest.mjs
+++ b/test/intl/Intl__ListFormatTest.mjs
@@ -5,12 +5,12 @@ console.log("---");
 
 console.log("Intl.ListFormat");
 
-new Intl.ListFormat(undefined, undefined);
+new Intl.ListFormat();
 
 new Intl.ListFormat([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 var _formatter = new Intl.ListFormat([
       "en-US",
@@ -23,7 +23,7 @@ var _formatter = new Intl.ListFormat([
 Intl.ListFormat.supportedLocalesOf([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 Intl.ListFormat.supportedLocalesOf([
       "en-US",
diff --git a/test/intl/Intl__LocaleTest.mjs b/test/intl/Intl__LocaleTest.mjs
index f58897c3..a8349a84 100644
--- a/test/intl/Intl__LocaleTest.mjs
+++ b/test/intl/Intl__LocaleTest.mjs
@@ -5,7 +5,7 @@ console.log("---");
 
 console.log("Intl.Locale");
 
-var _locale = new Intl.Locale("en-US", undefined);
+var _locale = new Intl.Locale("en-US");
 
 var locale = new Intl.Locale("en-US", {
       calendar: "hebrew",
diff --git a/test/intl/Intl__NumberFormatTest.mjs b/test/intl/Intl__NumberFormatTest.mjs
index 9f8e02d9..dfde8138 100644
--- a/test/intl/Intl__NumberFormatTest.mjs
+++ b/test/intl/Intl__NumberFormatTest.mjs
@@ -15,7 +15,7 @@ var currencyFormatter = new Intl.NumberFormat(["fr-FR"], {
 console.log(Intl.NumberFormat.supportedLocalesOf([
           "fr-FR",
           "en-US"
-        ], undefined));
+        ]));
 
 console.log(currencyFormatter.format(123.23));
 
diff --git a/test/intl/Intl__PluralRulesTest.mjs b/test/intl/Intl__PluralRulesTest.mjs
index 786eb15a..3ad44723 100644
--- a/test/intl/Intl__PluralRulesTest.mjs
+++ b/test/intl/Intl__PluralRulesTest.mjs
@@ -5,12 +5,12 @@ console.log("---");
 
 console.log("Intl.PluralRules");
 
-new Intl.PluralRules(undefined, undefined);
+new Intl.PluralRules();
 
 new Intl.PluralRules([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 var _formatter = new Intl.PluralRules(undefined, {
       type: "ordinal",
diff --git a/test/intl/Intl__RelativeTimeFormatTest.mjs b/test/intl/Intl__RelativeTimeFormatTest.mjs
index 2afbbac3..1bfd2627 100644
--- a/test/intl/Intl__RelativeTimeFormatTest.mjs
+++ b/test/intl/Intl__RelativeTimeFormatTest.mjs
@@ -8,7 +8,7 @@ console.log("Intl.RelativeTimeFormat");
 Intl.RelativeTimeFormat.supportedLocalesOf([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 Intl.RelativeTimeFormat.supportedLocalesOf([
       "en-US",
@@ -17,12 +17,12 @@ Intl.RelativeTimeFormat.supportedLocalesOf([
       localeMatcher: "lookup"
     });
 
-new Intl.RelativeTimeFormat(undefined, undefined);
+new Intl.RelativeTimeFormat();
 
 new Intl.RelativeTimeFormat([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 var _formatter = new Intl.RelativeTimeFormat(undefined, {
       numeric: "always",
diff --git a/test/intl/Intl__SegmenterTest.mjs b/test/intl/Intl__SegmenterTest.mjs
index c1d6ecf0..841c4ef6 100644
--- a/test/intl/Intl__SegmenterTest.mjs
+++ b/test/intl/Intl__SegmenterTest.mjs
@@ -8,7 +8,7 @@ console.log("Intl.Segmenter");
 Intl.Segmenter.supportedLocalesOf([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 Intl.Segmenter.supportedLocalesOf([
       "en-US",
@@ -17,12 +17,12 @@ Intl.Segmenter.supportedLocalesOf([
       localeMatcher: "lookup"
     });
 
-new Intl.Segmenter(undefined, undefined);
+new Intl.Segmenter();
 
 new Intl.Segmenter([
       "en-US",
       "en-GB"
-    ], undefined);
+    ]);
 
 var _formatter = new Intl.Segmenter(undefined, {
       granularity: "word"