diff --git a/src/renderer/src/components/editor/markdown-scanner-boundaries.test.ts b/src/renderer/src/components/editor/markdown-scanner-boundaries.test.ts
new file mode 100644
index 00000000000..305af2dfc12
--- /dev/null
+++ b/src/renderer/src/components/editor/markdown-scanner-boundaries.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it } from 'vitest'
+import { markdownCodeSpanRanges, markdownFenceRanges } from './markdown-scan-ranges'
+import { createMarkdownCodeSpanScanner } from './markdown-code-span-scanner'
+
+describe('standalone Markdown boundaries', () => {
+  it('rejects backticks in a backtick fence info string', () => {
+    expect(markdownFenceRanges('```bad`info\ntext')).toEqual([])
+    expect(markdownFenceRanges('~~~bad`info\ntext\n~~~')).toEqual([[0, 20]])
+  })
+
+  it('does not open a code span on an escaped backtick', () => {
+    expect(markdownCodeSpanRanges('\\`literal\\`')).toEqual([])
+    const scanner = createMarkdownCodeSpanScanner('\\`literal\\`')
+    expect(scanner.findSpanEnd(1)).toBeNull()
+  })
+
+  it('accepts CR-only fence lines', () => {
+    const source = '```\rcode\r```\rafter'
+    expect(markdownFenceRanges(source)).toEqual([[0, 13]])
+  })
+})