diff --git a/.gitignore b/.gitignore
index ae39564eb8a4..85c5685310a9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -72,3 +72,4 @@ packages/babel-standalone/babel.min.js
 /eslint/*/node_modules
 /eslint/*/LICENSE
 !/packages/babel-eslint-plugin/LICENSE
+/.vscode
diff --git a/packages/babel-helper-builder-react-jsx-experimental/src/index.js b/packages/babel-helper-builder-react-jsx-experimental/src/index.js
index d42d84c34063..00fee165933f 100644
--- a/packages/babel-helper-builder-react-jsx-experimental/src/index.js
+++ b/packages/babel-helper-builder-react-jsx-experimental/src/index.js
@@ -457,7 +457,7 @@ You can set \`throwIfNamespace: false\` to bypass this warning.`,
     }
 
     return makeTrace(
-      state.fileNameIdentifier,
+      t.cloneNode(state.fileNameIdentifier),
       location.start.line,
       location.start.column,
     );
diff --git a/packages/babel-helper-create-class-features-plugin/src/decorators.js b/packages/babel-helper-create-class-features-plugin/src/decorators.js
index 49444bbea4ac..b4fbcae13f08 100644
--- a/packages/babel-helper-create-class-features-plugin/src/decorators.js
+++ b/packages/babel-helper-create-class-features-plugin/src/decorators.js
@@ -137,7 +137,7 @@ export function buildDecoratedClass(ref, path, elements, file) {
   let replacement = template.expression.ast`
     ${addDecorateHelper(file)}(
       ${classDecorators || t.nullLiteral()},
-      function (${initializeId}, ${superClass ? superId : null}) {
+      function (${initializeId}, ${superClass ? t.cloneNode(superId) : null}) {
         ${node}
         return { F: ${t.cloneNode(node.id)}, d: ${definitions} };
       },
@@ -158,7 +158,7 @@ export function buildDecoratedClass(ref, path, elements, file) {
   }
 
   return {
-    instanceNodes: [template.statement.ast`${initializeId}(this)`],
+    instanceNodes: [template.statement.ast`${t.cloneNode(initializeId)}(this)`],
     wrapClass(path) {
       path.replaceWith(replacement);
       return path.get(classPathDesc);
diff --git a/packages/babel-helper-create-class-features-plugin/src/fields.js b/packages/babel-helper-create-class-features-plugin/src/fields.js
index 848b0033b675..6bb644f6d2b9 100644
--- a/packages/babel-helper-create-class-features-plugin/src/fields.js
+++ b/packages/babel-helper-create-class-features-plugin/src/fields.js
@@ -45,8 +45,9 @@ export function buildPrivateNamesNodes(privateNamesMap, loose, state) {
     // In spec mode, only instance fields need a "private name" initializer
     // because static fields are directly assigned to a variable in the
     // buildPrivateStaticFieldInitSpec function.
-    const { id, static: isStatic, method: isMethod, getId, setId } = value;
+    const { static: isStatic, method: isMethod, getId, setId } = value;
     const isAccessor = getId || setId;
+    const id = t.cloneNode(value.id);
     if (loose) {
       initNodes.push(
         template.statement.ast`
@@ -157,7 +158,7 @@ const privateInVisitor = privateNameVisitorFactory({
     if (loose) {
       const { id } = privateNamesMap.get(name);
       path.replaceWith(template.expression.ast`
-        Object.prototype.hasOwnProperty.call(${right}, ${id})
+        Object.prototype.hasOwnProperty.call(${right}, ${t.cloneNode(id)})
       `);
       return;
     }
@@ -169,7 +170,7 @@ const privateInVisitor = privateNameVisitorFactory({
       return;
     }
 
-    path.replaceWith(template.expression.ast`${id}.has(${right})`);
+    path.replaceWith(template.expression.ast`${t.cloneNode(id)}.has(${right})`);
   },
 });
 
@@ -327,8 +328,8 @@ const privateNameHandlerLoose = {
 
     return template.expression`BASE(REF, PROP)[PROP]`({
       BASE: file.addHelper("classPrivateFieldLooseBase"),
-      REF: object,
-      PROP: privateNamesMap.get(name).id,
+      REF: t.cloneNode(object),
+      PROP: t.cloneNode(privateNamesMap.get(name).id),
     });
   },
 
@@ -387,7 +388,7 @@ function buildPrivateFieldInitLoose(ref, prop, privateNamesMap) {
   const value = prop.node.value || prop.scope.buildUndefinedNode();
 
   return template.statement.ast`
-    Object.defineProperty(${ref}, ${id}, {
+    Object.defineProperty(${ref}, ${t.cloneNode(id)}, {
       // configurable is false by default
       // enumerable is false by default
       writable: true,
@@ -400,7 +401,7 @@ function buildPrivateInstanceFieldInitSpec(ref, prop, privateNamesMap) {
   const { id } = privateNamesMap.get(prop.node.key.id.name);
   const value = prop.node.value || prop.scope.buildUndefinedNode();
 
-  return template.statement.ast`${id}.set(${ref}, {
+  return template.statement.ast`${t.cloneNode(id)}.set(${ref}, {
     // configurable is always false for private elements
     // enumerable is always false for private elements
     writable: true,
@@ -422,7 +423,7 @@ function buildPrivateStaticFieldInitSpec(prop, privateNamesMap) {
     });
 
     return template.statement.ast`
-      var ${id.name} = {
+      var ${t.cloneNode(id)} = {
         // configurable is false by default
         // enumerable is false by default
         // writable is false by default
@@ -434,7 +435,7 @@ function buildPrivateStaticFieldInitSpec(prop, privateNamesMap) {
 
   const value = prop.node.value || prop.scope.buildUndefinedNode();
   return template.statement.ast`
-    var ${id} = {
+    var ${t.cloneNode(id)} = {
       // configurable is false by default
       // enumerable is false by default
       writable: true,
@@ -603,14 +604,14 @@ function buildPrivateMethodDeclaration(prop, privateNamesMap, loose = false) {
   if (isStatic && !loose) {
     return t.variableDeclaration("var", [
       t.variableDeclarator(
-        id,
+        t.cloneNode(id),
         t.functionExpression(id, params, body, generator, async),
       ),
     ]);
   }
 
   return t.variableDeclaration("var", [
-    t.variableDeclarator(methodId, methodValue),
+    t.variableDeclarator(t.cloneNode(methodId), methodValue),
   ]);
 }
 
diff --git a/packages/babel-helper-create-class-features-plugin/src/index.js b/packages/babel-helper-create-class-features-plugin/src/index.js
index fba10a68e8c4..d23c12cefdc1 100644
--- a/packages/babel-helper-create-class-features-plugin/src/index.js
+++ b/packages/babel-helper-create-class-features-plugin/src/index.js
@@ -1,3 +1,4 @@
+import { types as t } from "@babel/core";
 import nameFunction from "@babel/helper-function-name";
 import splitExportDeclaration from "@babel/helper-split-export-declaration";
 import {
@@ -129,7 +130,7 @@ export function createClassFeaturePlugin({
           nameFunction(path);
           ref = path.scope.generateUidIdentifier("class");
         } else {
-          ref = path.node.id;
+          ref = t.cloneNode(path.node.id);
         }
 
         // NODE: These three functions don't support decorators yet,
diff --git a/packages/babel-helper-create-class-features-plugin/src/misc.js b/packages/babel-helper-create-class-features-plugin/src/misc.js
index 31f8e0948676..8bb57a85df63 100644
--- a/packages/babel-helper-create-class-features-plugin/src/misc.js
+++ b/packages/babel-helper-create-class-features-plugin/src/misc.js
@@ -72,8 +72,14 @@ export function injectInitialization(path, constructor, nodes, renamer) {
   if (isDerived) {
     const bareSupers = [];
     constructor.traverse(findBareSupers, bareSupers);
+    let isFirst = true;
     for (const bareSuper of bareSupers) {
-      bareSuper.insertAfter(nodes);
+      if (isFirst) {
+        bareSuper.insertAfter(nodes);
+        isFirst = false;
+      } else {
+        bareSuper.insertAfter(nodes.map(n => t.cloneNode(n)));
+      }
     }
   } else {
     constructor.get("body").unshiftContainer("body", nodes);
diff --git a/packages/babel-helper-member-expression-to-functions/src/index.js b/packages/babel-helper-member-expression-to-functions/src/index.js
index 6620978c6bc6..4ea964fdb3bf 100644
--- a/packages/babel-helper-member-expression-to-functions/src/index.js
+++ b/packages/babel-helper-member-expression-to-functions/src/index.js
@@ -235,8 +235,12 @@ const handle = {
             t.binaryExpression(
               "===",
               baseNeedsMemoised
-                ? t.assignmentExpression("=", baseRef, startingNode)
-                : baseRef,
+                ? t.assignmentExpression(
+                    "=",
+                    t.cloneNode(baseRef),
+                    t.cloneNode(startingNode),
+                  )
+                : t.cloneNode(baseRef),
               t.nullLiteral(),
             ),
             t.binaryExpression(
@@ -263,7 +267,7 @@ const handle = {
               false,
               true,
             ),
-            [context, ...endParent.arguments],
+            [t.cloneNode(context), ...endParent.arguments],
             false,
           ),
         );
diff --git a/packages/babel-helper-module-transforms/src/rewrite-live-references.js b/packages/babel-helper-module-transforms/src/rewrite-live-references.js
index b98953f70662..f036d578b6ba 100644
--- a/packages/babel-helper-module-transforms/src/rewrite-live-references.js
+++ b/packages/babel-helper-module-transforms/src/rewrite-live-references.js
@@ -337,7 +337,9 @@ const rewriteReferencesVisitor = {
       path
         .get("left")
         .replaceWith(
-          t.variableDeclaration("let", [t.variableDeclarator(newLoopId)]),
+          t.variableDeclaration("let", [
+            t.variableDeclarator(t.cloneNode(newLoopId)),
+          ]),
         );
       scope.registerDeclaration(path.get("left"));
     }
diff --git a/packages/babel-helper-transform-fixture-test-runner/src/index.js b/packages/babel-helper-transform-fixture-test-runner/src/index.js
index 940b83a8cebb..ac00464f16e6 100644
--- a/packages/babel-helper-transform-fixture-test-runner/src/index.js
+++ b/packages/babel-helper-transform-fixture-test-runner/src/index.js
@@ -146,6 +146,7 @@ function run(task) {
   function getOpts(self) {
     const newOpts = merge(
       {
+        ast: true,
         cwd: path.dirname(self.loc),
         filename: self.loc,
         filenameRelative: self.filename,
diff --git a/packages/babel-plugin-proposal-async-generator-functions/src/for-await.js b/packages/babel-plugin-proposal-async-generator-functions/src/for-await.js
index 20198f1437e9..eff702a255b3 100644
--- a/packages/babel-plugin-proposal-async-generator-functions/src/for-await.js
+++ b/packages/babel-plugin-proposal-async-generator-functions/src/for-await.js
@@ -61,7 +61,7 @@ export default function (path, { getAsyncIterator }) {
     ITERATOR_KEY: scope.generateUidIdentifier("iterator"),
     GET_ITERATOR: getAsyncIterator,
     OBJECT: node.right,
-    STEP_VALUE: stepValue,
+    STEP_VALUE: t.cloneNode(stepValue),
     STEP_KEY: stepKey,
   });
 
diff --git a/packages/babel-plugin-proposal-decorators/src/transformer-legacy.js b/packages/babel-plugin-proposal-decorators/src/transformer-legacy.js
index f617ee0940fd..d860d884e82d 100644
--- a/packages/babel-plugin-proposal-decorators/src/transformer-legacy.js
+++ b/packages/babel-plugin-proposal-decorators/src/transformer-legacy.js
@@ -160,7 +160,7 @@ function applyTargetDecorators(path, state, decoratedProps) {
       acc = acc.concat([
         t.assignmentExpression(
           "=",
-          descriptor,
+          t.cloneNode(descriptor),
           t.callExpression(state.addHelper("applyDecoratedDescriptor"), [
             t.cloneNode(target),
             t.cloneNode(property),
diff --git a/packages/babel-plugin-proposal-function-bind/src/index.js b/packages/babel-plugin-proposal-function-bind/src/index.js
index ea62953863e5..0dea27804a15 100644
--- a/packages/babel-plugin-proposal-function-bind/src/index.js
+++ b/packages/babel-plugin-proposal-function-bind/src/index.js
@@ -7,7 +7,7 @@ export default declare(api => {
 
   function getTempId(scope) {
     let id = scope.path.getData("functionBind");
-    if (id) return id;
+    if (id) return t.cloneNode(id);
 
     id = scope.generateDeclaredUidIdentifier("context");
     return scope.path.setData("functionBind", id);
@@ -35,7 +35,7 @@ export default declare(api => {
         bind.callee.object,
       );
     }
-    return tempId;
+    return t.cloneNode(tempId);
   }
 
   return {
diff --git a/packages/babel-plugin-proposal-partial-application/src/index.js b/packages/babel-plugin-proposal-partial-application/src/index.js
index 8bd32c72c6f7..d9b18598b334 100644
--- a/packages/babel-plugin-proposal-partial-application/src/index.js
+++ b/packages/babel-plugin-proposal-partial-application/src/index.js
@@ -97,7 +97,7 @@ export default declare(api => {
               "=",
               t.cloneNode(functionLVal),
               t.memberExpression(
-                receiverLVal,
+                t.cloneNode(receiverLVal),
                 node.callee.property,
                 false,
                 false,
@@ -105,19 +105,19 @@ export default declare(api => {
             ),
             ...argsInitializers,
             t.functionExpression(
-              node.callee.property,
+              t.cloneNode(node.callee.property),
               placeholdersParams,
               t.blockStatement(
                 [
                   t.returnStatement(
                     t.callExpression(
                       t.memberExpression(
-                        functionLVal,
+                        t.cloneNode(functionLVal),
                         t.identifier("call"),
                         false,
                         false,
                       ),
-                      [receiverLVal, ...args],
+                      [t.cloneNode(receiverLVal), ...args],
                     ),
                   ),
                 ],
@@ -132,10 +132,14 @@ export default declare(api => {
             t.assignmentExpression("=", t.cloneNode(functionLVal), node.callee),
             ...argsInitializers,
             t.functionExpression(
-              node.callee,
+              t.cloneNode(node.callee),
               placeholdersParams,
               t.blockStatement(
-                [t.returnStatement(t.callExpression(functionLVal, args))],
+                [
+                  t.returnStatement(
+                    t.callExpression(t.cloneNode(functionLVal), args),
+                  ),
+                ],
                 [],
               ),
               false,
diff --git a/packages/babel-plugin-proposal-pipeline-operator/src/buildOptimizedSequenceExpression.js b/packages/babel-plugin-proposal-pipeline-operator/src/buildOptimizedSequenceExpression.js
index 2d0d3f23ea8f..f44ddf7cb843 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/src/buildOptimizedSequenceExpression.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/src/buildOptimizedSequenceExpression.js
@@ -30,7 +30,7 @@ const buildOptimizedSequenceExpression = ({ assign, call, path }) => {
 
     call.callee = evalSequence;
 
-    path.scope.push({ id: placeholderNode });
+    path.scope.push({ id: t.cloneNode(placeholderNode) });
 
     return t.sequenceExpression([assign, call]);
   }
@@ -40,7 +40,7 @@ const buildOptimizedSequenceExpression = ({ assign, call, path }) => {
     return t.sequenceExpression([pipelineLeft, calledExpression.body]);
   }
 
-  path.scope.push({ id: placeholderNode });
+  path.scope.push({ id: t.cloneNode(placeholderNode) });
 
   if (param) {
     path.get("right").scope.rename(param.name, placeholderNode.name);
diff --git a/packages/babel-plugin-proposal-pipeline-operator/src/smartVisitor.js b/packages/babel-plugin-proposal-pipeline-operator/src/smartVisitor.js
index 750d9767ddeb..4b41ffabba31 100644
--- a/packages/babel-plugin-proposal-pipeline-operator/src/smartVisitor.js
+++ b/packages/babel-plugin-proposal-pipeline-operator/src/smartVisitor.js
@@ -2,7 +2,7 @@ import { types as t } from "@babel/core";
 
 const updateTopicReferenceVisitor = {
   PipelinePrimaryTopicReference(path) {
-    path.replaceWith(this.topicId);
+    path.replaceWith(t.cloneNode(this.topicId));
   },
   PipelineTopicExpression(path) {
     path.skip();
diff --git a/packages/babel-plugin-transform-block-scoping/src/index.js b/packages/babel-plugin-transform-block-scoping/src/index.js
index 70f359d00c8b..c6a7fe26f48e 100644
--- a/packages/babel-plugin-transform-block-scoping/src/index.js
+++ b/packages/babel-plugin-transform-block-scoping/src/index.js
@@ -33,7 +33,7 @@ export default declare((api, opts) => {
             const decl = node.declarations[i];
             const assign = t.assignmentExpression(
               "=",
-              decl.id,
+              t.cloneNode(decl.id),
               decl.init || scope.buildUndefinedNode(),
             );
             assign._ignoreBlockScopingTDZ = true;
diff --git a/packages/babel-plugin-transform-modules-amd/src/index.js b/packages/babel-plugin-transform-modules-amd/src/index.js
index b69d8025be5d..7ea2b150f04b 100644
--- a/packages/babel-plugin-transform-modules-amd/src/index.js
+++ b/packages/babel-plugin-transform-modules-amd/src/index.js
@@ -71,8 +71,8 @@ export default declare((api, options) => {
             new Promise((${resolveId}, ${rejectId}) =>
               ${requireId}(
                 [${getImportSource(t, path.node)}],
-                imported => ${resolveId}(${result}),
-                ${rejectId}
+                imported => ${t.cloneNode(resolveId)}(${result}),
+                ${t.cloneNode(rejectId)}
               )
             )`,
         );
@@ -84,7 +84,7 @@ export default declare((api, options) => {
             if (requireId) {
               injectWrapper(
                 path,
-                buildAnonymousWrapper({ REQUIRE: requireId }),
+                buildAnonymousWrapper({ REQUIRE: t.cloneNode(requireId) }),
               );
             }
             return;
@@ -94,7 +94,7 @@ export default declare((api, options) => {
           const importNames = [];
           if (requireId) {
             amdArgs.push(t.stringLiteral("require"));
-            importNames.push(requireId);
+            importNames.push(t.cloneNode(requireId));
           }
 
           let moduleName = getModuleName(this.file.opts, options);
diff --git a/packages/babel-plugin-transform-modules-systemjs/src/index.js b/packages/babel-plugin-transform-modules-systemjs/src/index.js
index 0a4dfe74a72a..3431c5f45e6b 100644
--- a/packages/babel-plugin-transform-modules-systemjs/src/index.js
+++ b/packages/babel-plugin-transform-modules-systemjs/src/index.js
@@ -233,8 +233,8 @@ export default declare((api, options) => {
           }
         },
         exit(path, state) {
-          const undefinedIdent = path.scope.buildUndefinedNode();
-          const exportIdent = path.scope.generateUid("export");
+          const scope = path.scope;
+          const exportIdent = scope.generateUid("export");
           const contextIdent = state.contextIdent;
 
           const exportMap = Object.create(null);
@@ -285,7 +285,7 @@ export default declare((api, options) => {
               beforeBody.push(path.node);
               removedPaths.push(path);
             } else if (path.isClassDeclaration()) {
-              variableIds.push(path.node.id);
+              variableIds.push(t.cloneNode(path.node.id));
               path.replaceWith(
                 t.expressionStatement(
                   t.assignmentExpression(
@@ -299,7 +299,7 @@ export default declare((api, options) => {
               const source = path.node.source.value;
               pushModule(source, "imports", path.node.specifiers);
               for (const name of Object.keys(path.getBindingIdentifiers())) {
-                path.scope.removeBinding(name);
+                scope.removeBinding(name);
                 variableIds.push(t.identifier(name));
               }
               path.remove();
@@ -312,8 +312,8 @@ export default declare((api, options) => {
               if (declar.isClassDeclaration()) {
                 if (id) {
                   exportNames.push("default");
-                  exportValues.push(undefinedIdent);
-                  variableIds.push(id);
+                  exportValues.push(scope.buildUndefinedNode());
+                  variableIds.push(t.cloneNode(id));
                   addExportName(id.name, "default");
                   path.replaceWith(
                     t.expressionStatement(
@@ -360,8 +360,8 @@ export default declare((api, options) => {
                 } else if (path.isClass()) {
                   const name = declar.node.id.name;
                   exportNames.push(name);
-                  exportValues.push(undefinedIdent);
-                  variableIds.push(declar.node.id);
+                  exportValues.push(scope.buildUndefinedNode());
+                  variableIds.push(t.cloneNode(declar.node.id));
                   path.replaceWith(
                     t.expressionStatement(
                       t.assignmentExpression(
@@ -389,9 +389,7 @@ export default declare((api, options) => {
                     const nodes = [];
 
                     for (const specifier of specifiers) {
-                      const binding = path.scope.getBinding(
-                        specifier.local.name,
-                      );
+                      const binding = scope.getBinding(specifier.local.name);
                       // hoisted function export
                       if (
                         binding &&
@@ -426,7 +424,7 @@ export default declare((api, options) => {
 
           modules.forEach(function (specifiers) {
             let setterBody = [];
-            const target = path.scope.generateUid(specifiers.key);
+            const target = scope.generateUid(specifiers.key);
 
             for (let specifier of specifiers.imports) {
               if (t.isImportNamespaceSpecifier(specifier)) {
@@ -510,7 +508,7 @@ export default declare((api, options) => {
               variableIds.push(id);
               if (!hasInit) {
                 exportNames.push(name);
-                exportValues.push(undefinedIdent);
+                exportValues.push(scope.buildUndefinedNode());
               }
             },
             null,
@@ -540,7 +538,7 @@ export default declare((api, options) => {
           path.traverse(reassignmentVisitor, {
             exports: exportMap,
             buildCall: buildExportCall,
-            scope: path.scope,
+            scope,
           });
 
           for (const path of removedPaths) {
diff --git a/packages/babel-plugin-transform-parameters/src/params.js b/packages/babel-plugin-transform-parameters/src/params.js
index 51901e1a26ba..4608a225af45 100644
--- a/packages/babel-plugin-transform-parameters/src/params.js
+++ b/packages/babel-plugin-transform-parameters/src/params.js
@@ -229,6 +229,6 @@ function buildScopeIIFE(shadowedParams, body) {
   }
 
   return t.returnStatement(
-    t.callExpression(t.arrowFunctionExpression(params, body), params),
+    t.callExpression(t.arrowFunctionExpression(params, body), args),
   );
 }
diff --git a/packages/babel-plugin-transform-react-jsx-source/src/index.js b/packages/babel-plugin-transform-react-jsx-source/src/index.js
index fe258bb87f84..d68649955df0 100644
--- a/packages/babel-plugin-transform-react-jsx-source/src/index.js
+++ b/packages/babel-plugin-transform-react-jsx-source/src/index.js
@@ -82,7 +82,7 @@ export default declare(api => {
       }
 
       const trace = makeTrace(
-        state.fileNameIdentifier,
+        t.cloneNode(state.fileNameIdentifier),
         location.start.line,
         location.start.column,
       );
diff --git a/packages/babel-plugin-transform-runtime/src/index.js b/packages/babel-plugin-transform-runtime/src/index.js
index 0977b2b48b39..6559968ffa3c 100644
--- a/packages/babel-plugin-transform-runtime/src/index.js
+++ b/packages/babel-plugin-transform-runtime/src/index.js
@@ -301,7 +301,11 @@ export default declare((api, options, dirname) => {
               context2 = t.cloneNode(object);
             } else {
               context1 = path.scope.generateDeclaredUidIdentifier("context");
-              context2 = t.assignmentExpression("=", context1, object);
+              context2 = t.assignmentExpression(
+                "=",
+                t.cloneNode(context1),
+                object,
+              );
             }
             node.callee = t.memberExpression(
               t.callExpression(
diff --git a/packages/babel-plugin-transform-template-literals/src/index.js b/packages/babel-plugin-transform-template-literals/src/index.js
index 9ddbf5c9d3fc..abdf7087f8fc 100644
--- a/packages/babel-plugin-transform-template-literals/src/index.js
+++ b/packages/babel-plugin-transform-template-literals/src/index.js
@@ -87,9 +87,9 @@ export default declare((api, options) => {
         const lazyLoad = template.ast`
           function ${templateObject}() {
             const data = ${t.callExpression(helperId, callExpressionInput)};
-            ${templateObject} = function() { return data };
+            ${t.cloneNode(templateObject)} = function() { return data };
             return data;
-          } 
+          }
         `;
 
         scope.path.unshiftContainer("body", lazyLoad);
diff --git a/packages/babel-plugin-transform-typescript/src/index.js b/packages/babel-plugin-transform-typescript/src/index.js
index 82839fa05831..4aa2fcaa7aea 100644
--- a/packages/babel-plugin-transform-typescript/src/index.js
+++ b/packages/babel-plugin-transform-typescript/src/index.js
@@ -134,7 +134,8 @@ export default declare(
               );
             }
 
-            return template.statement.ast`this.${id} = ${id}`;
+            return template.statement.ast`
+              this.${t.cloneNode(id)} = ${t.cloneNode(id)}`;
           });
 
           injectInitialization(classPath, path, assigns);
diff --git a/packages/babel-plugin-transform-typescript/src/namespace.js b/packages/babel-plugin-transform-typescript/src/namespace.js
index 32d53447a80a..be3b51c949cd 100644
--- a/packages/babel-plugin-transform-typescript/src/namespace.js
+++ b/packages/babel-plugin-transform-typescript/src/namespace.js
@@ -156,16 +156,16 @@ function handleNested(path, t, node, parentExport) {
   let fallthroughValue = t.objectExpression([]);
 
   if (parentExport) {
+    const memberExpr = t.memberExpression(parentExport, realName);
     fallthroughValue = template.expression.ast`
-      ${parentExport}.${realName} || (
-        ${parentExport}.${realName} = ${fallthroughValue}
-      )
+      ${t.cloneNode(memberExpr)} ||
+        (${t.cloneNode(memberExpr)} = ${fallthroughValue})
     `;
   }
 
   return template.statement.ast`
     (function (${t.identifier(name)}) {
       ${namespaceTopLevel}
-    })(${realName} || (${realName} = ${fallthroughValue}));
+    })(${realName} || (${t.cloneNode(realName)} = ${fallthroughValue}));
   `;
 }