diff --git a/mon-entreprise/source/site/entry.en.tsx b/mon-entreprise/source/site/entry.en.tsx
index 6ea80221e..e357a387d 100644
--- a/mon-entreprise/source/site/entry.en.tsx
+++ b/mon-entreprise/source/site/entry.en.tsx
@@ -1,3 +1,7 @@
+// We disable Speedy mode for Styled-Component in production because it created a bug for overlay appearance
+// https://stackoverflow.com/questions/53486470/react-styled-components-stripped-out-from-production-build
+global.SC_DISABLE_SPEEDY = true
+
 import 'core-js/stable'
 import { hot } from 'react-hot-loader/root'
 import { render } from 'react-dom'
diff --git a/mon-entreprise/source/site/entry.fr.tsx b/mon-entreprise/source/site/entry.fr.tsx
index dc8daf1d0..496b24d28 100644
--- a/mon-entreprise/source/site/entry.fr.tsx
+++ b/mon-entreprise/source/site/entry.fr.tsx
@@ -1,3 +1,7 @@
+// We disable Speedy mode for Styled-Component in production because it created a bug for overlay appearance
+// https://stackoverflow.com/questions/53486470/react-styled-components-stripped-out-from-production-build
+global.SC_DISABLE_SPEEDY = true
+
 import { hot } from 'react-hot-loader/root'
 import 'core-js/stable'
 import 'react-hot-loader'
diff --git a/mon-entreprise/source/types/app-env.d.ts b/mon-entreprise/source/types/app-env.d.ts
index 59e04ecf6..bd0d28790 100644
--- a/mon-entreprise/source/types/app-env.d.ts
+++ b/mon-entreprise/source/types/app-env.d.ts
@@ -15,4 +15,8 @@ declare namespace NodeJS {
 		DEEPL_API_SECRET: string
 		INSEE_SIRENE_API_SECRET: string
 	}
+
+	interface Global {
+		SC_DISABLE_SPEEDY: boolean
+	}
 }