diff --git a/packages/frontend/src/components/global/MkPageHeader.vue b/packages/frontend/src/components/global/MkPageHeader.vue
index d5680b8413..6a926f7718 100644
--- a/packages/frontend/src/components/global/MkPageHeader.vue
+++ b/packages/frontend/src/components/global/MkPageHeader.vue
@@ -4,7 +4,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 -->
 
 <template>
-<div v-if="show" ref="el" :class="[$style.root]" :style="{ background: bg }">
+<div v-if="show" ref="el" :class="[$style.root]">
 	<div :class="[$style.upper, { [$style.slim]: narrow, [$style.thin]: thin_ }]">
 		<div v-if="!thin_ && narrow && props.displayMyAvatar && $i" class="_button" :class="$style.buttonsLeft" @click="openAccountMenu">
 			<MkAvatar :class="$style.avatar" :user="$i"/>
@@ -42,7 +42,6 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 <script lang="ts" setup>
 import { onMounted, onUnmounted, ref, inject, useTemplateRef, computed } from 'vue';
-import tinycolor from 'tinycolor2';
 import { scrollToTop } from '@@/js/scroll.js';
 import XTabs from './MkPageHeader.tabs.vue';
 import type { Tab } from './MkPageHeader.tabs.vue';
@@ -78,7 +77,6 @@ const hideTitle = computed(() => inject('shouldOmitHeaderTitle', false) || props
 const thin_ = props.thin || inject('shouldHeaderThin', false);
 
 const el = useTemplateRef('el');
-const bg = ref<string | undefined>(undefined);
 const narrow = ref(false);
 const hasTabs = computed(() => props.tabs.length > 0);
 const hasActions = computed(() => props.actions && props.actions.length > 0);
@@ -106,19 +104,9 @@ function onTabClick(): void {
 	top();
 }
 
-const calcBg = () => {
-	const rawBg = 'var(--MI_THEME-bg)';
-	const tinyBg = tinycolor(rawBg.startsWith('var(') ? getComputedStyle(window.document.documentElement).getPropertyValue(rawBg.slice(4, -1)) : rawBg);
-	tinyBg.setAlpha(0.85);
-	bg.value = tinyBg.toRgbString();
-};
-
 let ro: ResizeObserver | null;
 
 onMounted(() => {
-	calcBg();
-	globalEvents.on('themeChanging', calcBg);
-
 	if (el.value && el.value.parentElement) {
 		narrow.value = el.value.parentElement.offsetWidth < 500;
 		ro = new ResizeObserver((entries, observer) => {
@@ -131,13 +119,13 @@ onMounted(() => {
 });
 
 onUnmounted(() => {
-	globalEvents.off('themeChanging', calcBg);
 	if (ro) ro.disconnect();
 });
 </script>
 
 <style lang="scss" module>
 .root {
+	background: color(from var(--MI_THEME-bg) srgb r g b / 0.75);
 	-webkit-backdrop-filter: var(--MI-blur, blur(15px));
 	backdrop-filter: var(--MI-blur, blur(15px));
 	border-bottom: solid 0.5px var(--MI_THEME-divider);