diff --git a/.changeset/cool-starfishes-love.md b/.changeset/cool-starfishes-love.md
new file mode 100644
index 0000000000..c29ff03efc
--- /dev/null
+++ b/.changeset/cool-starfishes-love.md
@@ -0,0 +1,5 @@
+---
+'@backstage/theme': patch
+---
+
+Overwritting `PaletteOptions` & `ThemeOptions` type to allow usage of `createTheme` from `'@backstage/theme'` as well as `@material-ui/core/styles` with the same type. Additionally replacing default `CSSBaseline` wiht v4 instead of v5 for better backwards compatibilty for now.