diff --git a/packages/block-library/src/index.js b/packages/block-library/src/index.js
index 9cb2f44d05eb9b..56365c87a268fd 100644
--- a/packages/block-library/src/index.js
+++ b/packages/block-library/src/index.js
@@ -314,21 +314,21 @@ export const registerCoreBlocks = (
  * __experimentalRegisterExperimentalCoreBlocks( settings );
  * ```
  */
-export const __experimentalRegisterExperimentalCoreBlocks = process.env
-	.IS_GUTENBERG_PLUGIN
-	? ( { enableFSEBlocks } = {} ) => {
-			const enabledExperiments = [ enableFSEBlocks ? 'fse' : null ];
-			getAllBlocks()
-				.filter( ( { metadata } ) =>
-					isBlockMetadataExperimental( metadata )
-				)
-				.filter(
-					( { metadata: { __experimental } } ) =>
-						__experimental === true ||
-						enabledExperiments.includes( __experimental )
-				)
-				.forEach( ( { init } ) => init() );
-	  }
-	: undefined;
+export const __experimentalRegisterExperimentalCoreBlocks =
+	globalThis.IS_GUTENBERG_PLUGIN
+		? ( { enableFSEBlocks } = {} ) => {
+				const enabledExperiments = [ enableFSEBlocks ? 'fse' : null ];
+				getAllBlocks()
+					.filter( ( { metadata } ) =>
+						isBlockMetadataExperimental( metadata )
+					)
+					.filter(
+						( { metadata: { __experimental } } ) =>
+							__experimental === true ||
+							enabledExperiments.includes( __experimental )
+					)
+					.forEach( ( { init } ) => init() );
+		  }
+		: undefined;
 
 export { privateApis } from './private-apis';
diff --git a/packages/blocks/src/api/parser/convert-legacy-block.js b/packages/blocks/src/api/parser/convert-legacy-block.js
index c828a3f5db6c49..8396b98109792f 100644
--- a/packages/blocks/src/api/parser/convert-legacy-block.js
+++ b/packages/blocks/src/api/parser/convert-legacy-block.js
@@ -79,7 +79,7 @@ export function convertLegacyBlockNameAndAttributes( name, attributes ) {
 
 	// The following code is only relevant for the Gutenberg plugin.
 	// It's a stand-alone if statement for dead-code elimination.
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		// Convert pattern overrides added during experimental phase.
 		// Only four blocks were supported initially.
 		// These checks can be removed in WordPress 6.6.
diff --git a/packages/core-data/src/actions.js b/packages/core-data/src/actions.js
index 454250e8ad13c9..be4d12f0cb9ef6 100644
--- a/packages/core-data/src/actions.js
+++ b/packages/core-data/src/actions.js
@@ -396,7 +396,7 @@ export const editEntityRecord =
 			}, {} ),
 		};
 		if ( window.__experimentalEnableSync && entityConfig.syncConfig ) {
-			if ( process.env.IS_GUTENBERG_PLUGIN ) {
+			if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 				const objectId = entityConfig.getSyncObjectId( recordId );
 				getSyncProvider().update(
 					entityConfig.syncObjectType + '--edit',
diff --git a/packages/core-data/src/entities.js b/packages/core-data/src/entities.js
index e91744110faf32..8d09402087cf90 100644
--- a/packages/core-data/src/entities.js
+++ b/packages/core-data/src/entities.js
@@ -485,7 +485,7 @@ export const getOrLoadEntitiesConfig =
 
 		if ( configs?.length > 0 && hasConfig ) {
 			if ( window.__experimentalEnableSync ) {
-				if ( process.env.IS_GUTENBERG_PLUGIN ) {
+				if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 					registerSyncConfigs( configs );
 				}
 			}
@@ -506,7 +506,7 @@ export const getOrLoadEntitiesConfig =
 
 		configs = await loader.loadEntities();
 		if ( window.__experimentalEnableSync ) {
-			if ( process.env.IS_GUTENBERG_PLUGIN ) {
+			if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 				registerSyncConfigs( configs );
 			}
 		}
diff --git a/packages/core-data/src/resolvers.js b/packages/core-data/src/resolvers.js
index 7de2c354ba2bf8..ea77f342e69ca7 100644
--- a/packages/core-data/src/resolvers.js
+++ b/packages/core-data/src/resolvers.js
@@ -81,7 +81,7 @@ export const getEntityRecord =
 				entityConfig.syncConfig &&
 				! query
 			) {
-				if ( process.env.IS_GUTENBERG_PLUGIN ) {
+				if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 					const objectId = entityConfig.getSyncObjectId( key );
 
 					// Loads the persisted document.
diff --git a/packages/customize-widgets/src/index.js b/packages/customize-widgets/src/index.js
index 5b438cac86f49b..9afda775a1701c 100644
--- a/packages/customize-widgets/src/index.js
+++ b/packages/customize-widgets/src/index.js
@@ -61,7 +61,7 @@ export function initialize( editorName, blockEditorSettings ) {
 	} );
 	registerCoreBlocks( coreBlocks );
 	registerLegacyWidgetBlock();
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: ENABLE_EXPERIMENTAL_FSE_BLOCKS,
 		} );
diff --git a/packages/edit-post/src/components/visual-editor/index.js b/packages/edit-post/src/components/visual-editor/index.js
index 3bb50999c2a929..c1e13d79f29411 100644
--- a/packages/edit-post/src/components/visual-editor/index.js
+++ b/packages/edit-post/src/components/visual-editor/index.js
@@ -24,7 +24,7 @@ import { usePaddingAppender } from './use-padding-appender';
 
 const { EditorCanvas } = unlock( editorPrivateApis );
 
-const isGutenbergPlugin = process.env.IS_GUTENBERG_PLUGIN ? true : false;
+const isGutenbergPlugin = globalThis.IS_GUTENBERG_PLUGIN ? true : false;
 
 export default function VisualEditor( { styles } ) {
 	const {
diff --git a/packages/edit-post/src/index.js b/packages/edit-post/src/index.js
index 0a2d17a344e474..1e0b3fe7d4d6ff 100644
--- a/packages/edit-post/src/index.js
+++ b/packages/edit-post/src/index.js
@@ -80,7 +80,7 @@ export function initializeEditor(
 	registerCoreBlocks();
 	registerLegacyWidgetBlock( { inserter: false } );
 	registerWidgetGroupBlock( { inserter: false } );
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: settings.__unstableEnableFullSiteEditingBlocks,
 		} );
diff --git a/packages/edit-site/src/index.js b/packages/edit-site/src/index.js
index f42842f504e54d..41fc0a1985fded 100644
--- a/packages/edit-site/src/index.js
+++ b/packages/edit-site/src/index.js
@@ -42,7 +42,7 @@ export function initializeEditor( id, settings ) {
 	dispatch( blocksStore ).setFreeformFallbackBlockName( 'core/html' );
 	registerLegacyWidgetBlock( { inserter: false } );
 	registerWidgetGroupBlock( { inserter: false } );
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: true,
 		} );
diff --git a/packages/edit-widgets/src/index.js b/packages/edit-widgets/src/index.js
index eb87d22fefef9e..2374ec19dabd7b 100644
--- a/packages/edit-widgets/src/index.js
+++ b/packages/edit-widgets/src/index.js
@@ -73,7 +73,7 @@ export function initializeEditor( id, settings ) {
 	dispatch( blocksStore ).reapplyBlockTypeFilters();
 	registerCoreBlocks( coreBlocks );
 	registerLegacyWidgetBlock();
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		__experimentalRegisterExperimentalCoreBlocks( {
 			enableFSEBlocks: ENABLE_EXPERIMENTAL_FSE_BLOCKS,
 		} );
diff --git a/packages/editor/src/bindings/index.js b/packages/editor/src/bindings/index.js
index ce77b87ebc7a5c..5824cdde022cc6 100644
--- a/packages/editor/src/bindings/index.js
+++ b/packages/editor/src/bindings/index.js
@@ -13,6 +13,6 @@ import postMeta from './post-meta';
 const { registerBlockBindingsSource } = unlock( dispatch( blocksStore ) );
 registerBlockBindingsSource( postMeta );
 
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	registerBlockBindingsSource( patternOverrides );
 }
diff --git a/packages/editor/src/components/post-actions/actions.js b/packages/editor/src/components/post-actions/actions.js
index 194dd338f49e61..88387f336c159a 100644
--- a/packages/editor/src/components/post-actions/actions.js
+++ b/packages/editor/src/components/post-actions/actions.js
@@ -1019,7 +1019,7 @@ export function usePostActions( postType, onActionPerformed ) {
 			isTemplateOrTemplatePart && deleteTemplateAction,
 			! isTemplateOrTemplatePart && permanentlyDeletePostAction,
 			postRevisionsAction,
-			process.env.IS_GUTENBERG_PLUGIN
+			globalThis.IS_GUTENBERG_PLUGIN
 				? ! isTemplateOrTemplatePart &&
 				  ! isPattern &&
 				  duplicatePostAction
diff --git a/packages/interactivity-router/src/index.js b/packages/interactivity-router/src/index.js
index 7e786700338f50..35baa8bced4bbc 100644
--- a/packages/interactivity-router/src/index.js
+++ b/packages/interactivity-router/src/index.js
@@ -58,7 +58,7 @@ const fetchPage = async ( url, { html } ) => {
 const regionsToVdom = async ( dom, { vdom } = {} ) => {
 	const regions = {};
 	let head;
-	if ( process.env.IS_GUTENBERG_PLUGIN ) {
+	if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 		if ( navigationMode === 'fullPage' ) {
 			head = await fetchHeadAssets( dom, headElements );
 			regions.body = vdom
@@ -83,7 +83,7 @@ const regionsToVdom = async ( dom, { vdom } = {} ) => {
 // Render all interactive regions contained in the given page.
 const renderRegions = ( page ) => {
 	batch( () => {
-		if ( process.env.IS_GUTENBERG_PLUGIN ) {
+		if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 			if ( navigationMode === 'fullPage' ) {
 				// Once this code is tested and more mature, the head should be updated for region based navigation as well.
 				updateHead( page.head );
@@ -139,7 +139,7 @@ window.addEventListener( 'popstate', async () => {
 
 // Initialize the router and cache the initial page using the initial vDOM.
 // Once this code is tested and more mature, the head should be updated for region based navigation as well.
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	if ( navigationMode === 'fullPage' ) {
 		// Cache the scripts. Has to be called before fetching the assets.
 		[].map.call( document.querySelectorAll( 'script[src]' ), ( script ) => {
@@ -329,7 +329,7 @@ export const { state, actions } = store( 'core/router', {
 } );
 
 // Add click and prefetch to all links.
-if ( process.env.IS_GUTENBERG_PLUGIN ) {
+if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 	if ( navigationMode === 'fullPage' ) {
 		// Navigate on click.
 		document.addEventListener(
diff --git a/test/integration/full-content/full-content.test.js b/test/integration/full-content/full-content.test.js
index f825de04771442..4522dd7b88e451 100644
--- a/test/integration/full-content/full-content.test.js
+++ b/test/integration/full-content/full-content.test.js
@@ -82,7 +82,7 @@ describe( 'full post content fixture', () => {
 			formSubmissionNotification,
 		] );
 
-		if ( process.env.IS_GUTENBERG_PLUGIN ) {
+		if ( globalThis.IS_GUTENBERG_PLUGIN ) {
 			__experimentalRegisterExperimentalCoreBlocks( {
 				enableFSEBlocks: true,
 			} );