diff --git a/src/lib/dev-environment/dev-environment-core.js b/src/lib/dev-environment/dev-environment-core.js
index 85de7bbb19..d34fb6cf79 100644
--- a/src/lib/dev-environment/dev-environment-core.js
+++ b/src/lib/dev-environment/dev-environment-core.js
@@ -352,6 +352,7 @@ export function readEnvironmentData( slug: string ): InstanceData {
 
 	if ( instanceData.mailhog ) {
 		instanceData.mailpit = instanceData.mailhog;
+		delete instanceData.mailhog;
 	}
 
 	return instanceData;