diff --git a/packages/frontend/src/components/MkContainer.vue b/packages/frontend/src/components/MkContainer.vue
index d2d0fa3e4..f7cc697d6 100644
--- a/packages/frontend/src/components/MkContainer.vue
+++ b/packages/frontend/src/components/MkContainer.vue
@@ -34,7 +34,7 @@
 </template>
 
 <script lang="ts" setup>
-import { onMounted, ref, shallowRef, watch } from 'vue';
+import { onMounted, onUnmounted, ref, shallowRef, watch } from 'vue';
 import { defaultStore } from '@/store';
 import { i18n } from '@/i18n';
 
@@ -83,13 +83,19 @@ function afterLeave(el) {
 
 const calcOmit = () => {
 	if (omitted.value || ignoreOmit.value || props.maxHeight == null) return;
+	if (!contentEl.value) return;
 	const height = contentEl.value.offsetHeight;
 	omitted.value = height > props.maxHeight;
 };
 
+const omitObserver = new ResizeObserver((entries, observer) => {
+	calcOmit();
+});
+
 onMounted(() => {
 	watch(showBody, v => {
-		const headerHeight = props.showHeader ? headerEl.value.offsetHeight : 0;
+		if (!rootEl.value) return;
+		const headerHeight = props.showHeader ? headerEl.value?.offsetHeight ?? 0 : 0;
 		rootEl.value.style.minHeight = `${headerHeight}px`;
 		if (v) {
 			rootEl.value.style.flexBasis = 'auto';
@@ -100,13 +106,15 @@ onMounted(() => {
 		immediate: true,
 	});
 
-	rootEl.value.style.setProperty('--maxHeight', props.maxHeight + 'px');
+	if (rootEl.value) rootEl.value.style.setProperty('--maxHeight', props.maxHeight + 'px');
 
 	calcOmit();
 
-	new ResizeObserver((entries, observer) => {
-		calcOmit();
-	}).observe(contentEl.value);
+	if (contentEl.value) omitObserver.observe(contentEl.value);
+});
+
+onUnmounted(() => {
+	omitObserver.disconnect();
 });
 </script>
 
diff --git a/packages/frontend/src/components/MkModal.vue b/packages/frontend/src/components/MkModal.vue
index a33bb2d0e..b9ce6de69 100644
--- a/packages/frontend/src/components/MkModal.vue
+++ b/packages/frontend/src/components/MkModal.vue
@@ -17,7 +17,7 @@
 </template>
 
 <script lang="ts" setup>
-import { nextTick, onMounted, watch, provide } from 'vue';
+import { nextTick, onMounted, watch, provide, onUnmounted } from 'vue';
 import * as os from '@/os';
 import { isTouchUsing } from '@/scripts/touch';
 import { defaultStore } from '@/store';
@@ -38,7 +38,7 @@ type ModalTypes = 'popup' | 'dialog' | 'drawer';
 const props = withDefaults(defineProps<{
 	manualShowing?: boolean | null;
 	anchor?: { x: string; y: string; };
-	src?: HTMLElement;
+	src?: HTMLElement | null;
 	preferType?: ModalTypes | 'auto';
 	zPriority?: 'low' | 'middle' | 'high';
 	noOverlap?: boolean;
@@ -264,6 +264,10 @@ const onOpened = () => {
 	}, { passive: true });
 };
 
+const alignObserver = new ResizeObserver((entries, observer) => {
+	align();
+});
+
 onMounted(() => {
 	watch(() => props.src, async () => {
 		if (props.src) {
@@ -278,12 +282,14 @@ onMounted(() => {
 	}, { immediate: true });
 
 	nextTick(() => {
-		new ResizeObserver((entries, observer) => {
-			align();
-		}).observe(content!);
+		alignObserver.observe(content!);
 	});
 });
 
+onUnmounted(() => {
+	alignObserver.disconnect();
+});
+
 defineExpose({
 	close,
 });
diff --git a/packages/frontend/src/components/MkOmit.vue b/packages/frontend/src/components/MkOmit.vue
index e2d68d12c..668f9ff5a 100644
--- a/packages/frontend/src/components/MkOmit.vue
+++ b/packages/frontend/src/components/MkOmit.vue
@@ -8,7 +8,7 @@
 </template>
 
 <script lang="ts" setup>
-import { onMounted } from 'vue';
+import { onMounted, onUnmounted } from 'vue';
 import { i18n } from '@/i18n';
 
 const props = withDefaults(defineProps<{
@@ -21,16 +21,22 @@ let content = $shallowRef<HTMLElement>();
 let omitted = $ref(false);
 let ignoreOmit = $ref(false);
 
-onMounted(() => {
-	const calcOmit = () => {
-		if (omitted || ignoreOmit) return;
-		omitted = content.offsetHeight > props.maxHeight;
-	};
+const calcOmit = () => {
+	if (omitted || ignoreOmit) return;
+	omitted = content.offsetHeight > props.maxHeight;
+};
 
+const omitObserver = new ResizeObserver((entries, observer) => {
 	calcOmit();
-	new ResizeObserver((entries, observer) => {
-		calcOmit();
-	}).observe(content);
+});
+
+onMounted(() => {
+	calcOmit();
+	omitObserver.observe(content);
+});
+
+onUnmounted(() => {
+	omitObserver.disconnect();
 });
 </script>