diff --git a/.changeset/polite-seas-rule.md b/.changeset/polite-seas-rule.md
new file mode 100644
index 000000000..26d2ed7a1
--- /dev/null
+++ b/.changeset/polite-seas-rule.md
@@ -0,0 +1,5 @@
+---
+'@sveltejs/vite-plugin-svelte': patch
+---
+
+ignore keyup events without key in inspector
diff --git a/packages/vite-plugin-svelte/src/ui/inspector/Inspector.svelte b/packages/vite-plugin-svelte/src/ui/inspector/Inspector.svelte
index 41addcaf6..fde6bbe25 100644
--- a/packages/vite-plugin-svelte/src/ui/inspector/Inspector.svelte
+++ b/packages/vite-plugin-svelte/src/ui/inspector/Inspector.svelte
@@ -99,7 +99,7 @@
 	}
 
 	function keydown(event) {
-		if (event.repeat || event.key === undefined) {
+		if (event.repeat || event.key == null) {
 			return;
 		}
 
@@ -112,7 +112,7 @@
 	}
 
 	function keyup(event) {
-		if (event.repeat) {
+		if (event.repeat || event.key == null) {
 			return;
 		}
 		const k = event.key.toLowerCase();