diff --git a/apps/theming/REUSE.toml b/apps/theming/REUSE.toml
index bfac67174f9..c05da082002 100644
--- a/apps/theming/REUSE.toml
+++ b/apps/theming/REUSE.toml
@@ -22,13 +22,13 @@ SPDX-FileCopyrightText = "2022 Nextcloud GmbH and Nextcloud contributors"
 SPDX-License-Identifier = "AGPL-3.0-or-later"
 
 [[annotations]]
-path = ["img/background/jo-myoung-hee-fluid.webp", "img/background/jo-myoung-hee-fluid-dark.webp", "img/background/preview/jo-myoung-hee-fluid.jpg"]
+path = ["img/background/jo-myoung-hee-fluid.webp", "img/background/jo-myoung-hee-fluid-dark.webp", "img/background/preview/jo-myoung-hee-fluid.webp"]
 precedence = "aggregate"
 SPDX-FileCopyrightText = "2025 Nextcloud GmbH"
 SPDX-License-Identifier = "CC-BY-SA-4.0"
 
 [[annotations]]
-path = ["img/background/jenna-kim-the-globe.webp", "img/background/jenna-kim-the-globe-dark.webp", "img/background/preview/jenna-kim-the-globe.jpg"]
+path = ["img/background/jenna-kim-the-globe.webp", "img/background/jenna-kim-the-globe-dark.webp", "img/background/preview/jenna-kim-the-globe.webp"]
 precedence = "aggregate"
 SPDX-FileCopyrightText = "2024 Nextcloud GmbH"
 SPDX-License-Identifier = "CC-BY-SA-4.0"
diff --git a/apps/theming/img/background/preview/jenna-kim-the-globe.jpg b/apps/theming/img/background/preview/jenna-kim-the-globe.jpg
deleted file mode 100644
index 3b98d2828cd..00000000000
Binary files a/apps/theming/img/background/preview/jenna-kim-the-globe.jpg and /dev/null differ
diff --git a/apps/theming/img/background/preview/jenna-kim-the-globe.webp b/apps/theming/img/background/preview/jenna-kim-the-globe.webp
new file mode 100644
index 00000000000..0329e39c65e
Binary files /dev/null and b/apps/theming/img/background/preview/jenna-kim-the-globe.webp differ
diff --git a/apps/theming/img/background/preview/jo-myoung-hee-fluid.jpg b/apps/theming/img/background/preview/jo-myoung-hee-fluid.jpg
deleted file mode 100644
index 8c630f7d9b9..00000000000
Binary files a/apps/theming/img/background/preview/jo-myoung-hee-fluid.jpg and /dev/null differ
diff --git a/apps/theming/img/background/preview/jo-myoung-hee-fluid.webp b/apps/theming/img/background/preview/jo-myoung-hee-fluid.webp
new file mode 100644
index 00000000000..b3dd9fcb375
Binary files /dev/null and b/apps/theming/img/background/preview/jo-myoung-hee-fluid.webp differ
diff --git a/cypress/e2e/theming/themingUtils.ts b/cypress/e2e/theming/themingUtils.ts
index b4740beda1c..668503697da 100644
--- a/cypress/e2e/theming/themingUtils.ts
+++ b/cypress/e2e/theming/themingUtils.ts
@@ -5,7 +5,7 @@
 import { colord } from 'colord'
 
 export const defaultPrimary = '#00679e'
-export const defaultBackground = 'jenna-kim-the-globe.webp'
+export const defaultBackground = 'jo-myoung-hee-fluid.webp'
 
 /**
  * Check if a CSS variable is set to a specific color