diff --git a/src/babel/transformation/templates/ludicrous-in.js b/src/babel/transformation/templates/ludicrous-in.js
new file mode 100644
index 0000000000..80348f0da7
--- /dev/null
+++ b/src/babel/transformation/templates/ludicrous-in.js
@@ -0,0 +1 @@
+Object(RIGHT)[LEFT] !== undefined;
diff --git a/src/babel/transformation/transformers/es1/ludicrous.js b/src/babel/transformation/transformers/es1/ludicrous.js
deleted file mode 100644
index 27d9045c11..0000000000
--- a/src/babel/transformation/transformers/es1/ludicrous.js
+++ /dev/null
@@ -1,5 +0,0 @@
-import * as t from "../../../types";
-
-export var metadata = {
-  optional: true
-};
diff --git a/src/babel/transformation/transformers/index.js b/src/babel/transformation/transformers/index.js
index 80570ae174..373c956936 100644
--- a/src/babel/transformation/transformers/index.js
+++ b/src/babel/transformation/transformers/index.js
@@ -101,8 +101,8 @@ export default {
   "es7.doExpressions":                     require("./es7/do-expressions"),
 
   "es6.spec.symbols":                      require("./es6/spec.symbols"),
+  ludicrous:                               require("./other/ludicrous"),
   "spec.undefinedToVoid":                  require("./spec/undefined-to-void"),
-  "es1.ludicrous":                         require("./es1/ludicrous"),
 
   _strict:                                 require("./internal/strict"),
   _moduleFormatter:                        require("./internal/module-formatter"),
diff --git a/src/babel/transformation/transformers/other/ludicrous.js b/src/babel/transformation/transformers/other/ludicrous.js
new file mode 100644
index 0000000000..e240018e47
--- /dev/null
+++ b/src/babel/transformation/transformers/other/ludicrous.js
@@ -0,0 +1,29 @@
+import * as t from "../../../types";
+import * as util from "../../../util";
+
+export var metadata = {
+  optional: true
+};
+
+export function BinaryExpression(node) {
+  if (node.operator === "in") {
+    return util.template("ludicrous-in", {
+      LEFT: node.left,
+      RIGHT: node.right
+    });
+  }
+}
+
+export function Property(node) {
+  var key = node.key;
+  if (t.isLiteral(key) && typeof key.value === "number") {
+    key.value = "" + key.value;
+  }
+}
+
+export function Literal(node) {
+  if (node.regex) {
+    node.regex.pattern = "foobar";
+    node.regex.flags = "";
+  }
+}