diff --git a/packages/gatsby/cache-dir/__tests__/dev-loader-lazy.js b/packages/gatsby/cache-dir/__tests__/dev-loader-lazy.js
index dedcaa202dd0c..ff9df0b8d755c 100644
--- a/packages/gatsby/cache-dir/__tests__/dev-loader-lazy.js
+++ b/packages/gatsby/cache-dir/__tests__/dev-loader-lazy.js
@@ -29,7 +29,7 @@ describe(`Dev loader`, () => {
     global.__BASE_PATH__ = ``
     global.__PATH_PREFIX__ = ``
     process.env = Object.assign(process.env, {
-      GATSBY_EXPERIMENT_LAZY_DEVJS: true,
+      GATSBY_EXPERIMENTAL_LAZY_DEVJS: true,
     })
   })
 
@@ -37,7 +37,7 @@ describe(`Dev loader`, () => {
     global.__BASE_PATH__ = originalBasePath
     global.__PATH_PREFIX__ = originalPathPrefix
     process.env = Object.assign(process.env, {
-      GATSBY_EXPERIMENT_LAZY_DEVJS: false,
+      GATSBY_EXPERIMENTAL_LAZY_DEVJS: false,
     })
   })
 
diff --git a/packages/gatsby/cache-dir/app.js b/packages/gatsby/cache-dir/app.js
index 9711e0d331920..9dc0e474ac081 100644
--- a/packages/gatsby/cache-dir/app.js
+++ b/packages/gatsby/cache-dir/app.js
@@ -14,7 +14,7 @@ import matchPaths from "$virtual/match-paths.json"
 window.___emitter = emitter
 
 let pageComponentRequires
-if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
   pageComponentRequires = require(`$virtual/lazy-client-sync-requires`)
 } else {
   pageComponentRequires = require(`$virtual/sync-requires`)
diff --git a/packages/gatsby/cache-dir/dev-loader.js b/packages/gatsby/cache-dir/dev-loader.js
index 42bc6d3754955..e40b1eb902118 100644
--- a/packages/gatsby/cache-dir/dev-loader.js
+++ b/packages/gatsby/cache-dir/dev-loader.js
@@ -24,7 +24,7 @@ function mergePageEntry(cachedPage, newPageData) {
 class DevLoader extends BaseLoader {
   constructor(syncRequires, matchPaths) {
     let loadComponent
-    if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+    if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
       const ensureComponentInBundle = require(`./ensure-page-component-in-bundle`)
       loadComponent = chunkName => ensureComponentInBundle.default(chunkName)
     } else {
diff --git a/packages/gatsby/cache-dir/gatsby-browser-entry.js b/packages/gatsby/cache-dir/gatsby-browser-entry.js
index 7a48aab4c87fd..6110c46f8f1c5 100644
--- a/packages/gatsby/cache-dir/gatsby-browser-entry.js
+++ b/packages/gatsby/cache-dir/gatsby-browser-entry.js
@@ -20,7 +20,7 @@ const StaticQueryContext = React.createContext({})
 function StaticQueryDataRenderer({ staticQueryData, data, query, render }) {
   let combinedStaticQueryData = staticQueryData
 
-  if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+  if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
     // when we remove the flag, we don't need to combine them
     // w/ changes @pieh made.
     combinedStaticQueryData = {
@@ -83,7 +83,7 @@ useStaticQuery(graphql\`${query}\`);
   }
 
   let queryNotFound = false
-  if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+  if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
     // Merge data loaded via socket.io & xhr
     // when we remove the flag, we don't need to combine them
     // w/ changes @pieh made.
diff --git a/packages/gatsby/cache-dir/loader.js b/packages/gatsby/cache-dir/loader.js
index 2a37a88da6ded..bf2c925114603 100644
--- a/packages/gatsby/cache-dir/loader.js
+++ b/packages/gatsby/cache-dir/loader.js
@@ -144,7 +144,7 @@ export class BaseLoader {
           // In development, check if the page is in the bundle yet.
           if (
             process.env.NODE_ENV === `development` &&
-            process.env.GATSBY_EXPERIMENT_LAZY_DEVJS
+            process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS
           ) {
             const ensureComponentInBundle = require(`./ensure-page-component-in-bundle`)
               .default
diff --git a/packages/gatsby/src/bootstrap/requires-writer.ts b/packages/gatsby/src/bootstrap/requires-writer.ts
index fe7c67241a9c9..d607937f861df 100644
--- a/packages/gatsby/src/bootstrap/requires-writer.ts
+++ b/packages/gatsby/src/bootstrap/requires-writer.ts
@@ -187,7 +187,7 @@ export const writeAll = async (state: IGatsbyState): Promise<boolean> => {
 
   let cleanedClientVisitedPageComponents: Array<IGatsbyPageComponent> = components
   let notVisitedPageComponents: Array<IGatsbyPageComponent> = components
-  if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+  if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
     const clientVisitedPageComponents = [...state.clientVisitedPages.values()]
     // Remove any page components that no longer exist.
     cleanedClientVisitedPageComponents = components.filter(component =>
@@ -249,7 +249,7 @@ const preferDefault = m => (m && m.default) || m
   // file so we need a seperate one for each webpack instance.
   writeModule(`$virtual/ssr-sync-requires`, syncRequires)
 
-  if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+  if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
     // Create file with sync requires of visited page components files.
     let lazyClientSyncRequires = `${hotImport}
   // prefer default export if available
@@ -331,7 +331,7 @@ const preferDefault = m => (m && m.default) || m
   return true
 }
 
-if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
   /**
    * Start listening to CREATE_CLIENT_VISITED_PAGE events so we can rewrite
    * files as required
diff --git a/packages/gatsby/src/utils/start-server.ts b/packages/gatsby/src/utils/start-server.ts
index c71155388606c..b478c2de1cb01 100644
--- a/packages/gatsby/src/utils/start-server.ts
+++ b/packages/gatsby/src/utils/start-server.ts
@@ -127,7 +127,7 @@ export async function startServer(
   let cancelDevJSNotice: CancelExperimentNoticeCallbackOrUndefined
   if (
     process.env.gatsby_executing_command === `develop` &&
-    !process.env.GATSBY_EXPERIMENT_DEVJS_LAZY &&
+    !process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS &&
     !isCI()
   ) {
     cancelDevJSNotice = showExperimentNoticeAfterTimeout(
@@ -139,7 +139,7 @@ Your friendly Gatsby maintainers detected your site takes longer than ideal to b
 
 If you're interested in trialing out one of these future improvements *today* which should make your local development experience faster, go ahead and run your site with LAZY_DEVJS enabled.
 
-GATSBY_EXPERIMENT_DEVJS_LAZY=true gatsby develop
+GATSBY_EXPERIMENTAL_LAZY_DEVJS=true gatsby develop
 
 Please do let us know how it goes (good, bad, or otherwise) at https://gatsby.dev/lazy-devjs-umbrella
       `),
@@ -157,7 +157,7 @@ Please do let us know how it goes (good, bad, or otherwise) at https://gatsby.de
 
   const compiler = webpack(devConfig)
 
-  if (process.env.GATSBY_EXPERIMENT_LAZY_DEVJS) {
+  if (process.env.GATSBY_EXPERIMENTAL_LAZY_DEVJS) {
     const bodyParser = require(`body-parser`)
     const { boundActionCreators } = require(`../redux/actions`)
     const { createClientVisitedPage } = boundActionCreators