diff --git a/src/stores/contextKeyStore.ts b/src/stores/contextKeyStore.ts
index 9da1de800..6ea13b2e3 100644
--- a/src/stores/contextKeyStore.ts
+++ b/src/stores/contextKeyStore.ts
@@ -10,14 +10,19 @@ import { reactive } from 'vue'
  */
 function tokenize(expr: string): { t: string }[] {
   const tokens: { t: string }[] = []
+  let pos = 0
   const re =
     /\s*("(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'|==|!=|&&|\|\||[A-Za-z0-9_.]+|!|\(|\))\s*/g
   let m: RegExpExecArray | null
   while ((m = re.exec(expr))) {
+    if (m.index !== pos) {
+      throw new Error(`Invalid character in expression at pos ${pos}`)
+    }
     tokens.push({ t: m[1] })
+    pos = re.lastIndex
   }
-  if (re.lastIndex !== expr.length) {
-    throw new Error(`Invalid character in expression at pos ${re.lastIndex}`)
+  if (pos !== expr.length) {
+    throw new Error(`Invalid character in expression at pos ${pos}`)
   }
   return tokens
 }
diff --git a/tests-ui/tests/store/contextKeyStore.spec.ts b/tests-ui/tests/store/contextKeyStore.spec.ts
index 1a01e73f5..5f0da3918 100644
--- a/tests-ui/tests/store/contextKeyStore.spec.ts
+++ b/tests-ui/tests/store/contextKeyStore.spec.ts
@@ -11,6 +11,13 @@ describe('evalAst via evaluateCondition', () => {
     store = useContextKeyStore()
   })
 
+  it('evaluates logical OR correctly', () => {
+    store.setContextKey('a', true)
+    store.setContextKey('b', false)
+    const result = store.evaluateCondition('a || b')
+    expect(result).toBe(true)
+  })
+
   it('evaluates logical AND and NOT correctly', () => {
     store.setContextKey('a', true)
     store.setContextKey('b', false)