diff --git a/src/card.ts b/src/card.ts
index bd43f6d..b69d546 100644
--- a/src/card.ts
+++ b/src/card.ts
@@ -35,7 +35,9 @@ export function ignoreDiagnostic(view: EditorView, diag: Diagnostic, extraEffect
   }
   const { diagnostics } = view.state.field(diagnosticsField);
   const filtered = diagnostics.filter(d =>
-    !(d.from === diag.from && d.to === diag.to && d.lintKind === diag.lintKind),
+    diag.problemText
+      ? d.problemText !== diag.problemText
+      : !(d.from === diag.from && d.to === diag.to && d.lintKind === diag.lintKind),
   );
   view.dispatch({ effects: [setDiagnosticsEffect.of(filtered), ...extraEffects] });
 }
diff --git a/tests/card.test.ts b/tests/card.test.ts
index 9f92e69..e9d4f19 100644
--- a/tests/card.test.ts
+++ b/tests/card.test.ts
@@ -1,5 +1,89 @@
-import { describe, expect, it } from 'vitest';
-import { cardContentCSS } from '../src/card';
+import { describe, expect, it, vi } from 'vitest';
+import { EditorState } from '@codemirror/state';
+import type { EditorView } from '@codemirror/view';
+import { diagnosticsField, setDiagnosticsEffect } from '../src/decoration';
+import type { Diagnostic } from '../src/decoration';
+
+vi.mock('../src/lint', () => ({
+  shouldAddToDict: false,
+  addToDictionary: vi.fn(),
+}));
+
+// Import after mock so the module picks up the mocked lint
+const { cardContentCSS, ignoreDiagnostic } = await import('../src/card');
+
+function makeDiag(overrides: Partial<Diagnostic> & { from: number; to: number }): Diagnostic {
+  return {
+    lintKind: 'Spelling',
+    title: 'Spelling',
+    messageHtml: '<p>Unknown word</p>',
+    problemText: 'MarkEdit',
+    actions: [],
+    ...overrides,
+  };
+}
+
+function createMockView(diagnostics: Diagnostic[]) {
+  const state = EditorState.create({ extensions: [diagnosticsField] })
+    .update({ effects: setDiagnosticsEffect.of(diagnostics) }).state;
+
+  let dispatched: Diagnostic[] | undefined;
+  const view = {
+    state,
+    dispatch(tr: { effects: unknown[] }) {
+      for (const e of tr.effects) {
+        if ((e as { is: (t: unknown) => boolean }).is(setDiagnosticsEffect)) {
+          dispatched = (e as { value: Diagnostic[] }).value;
+        }
+      }
+    },
+  } as unknown as EditorView;
+
+  return { view, getDispatched: () => dispatched };
+}
+
+describe('ignoreDiagnostic', () => {
+  it('removes all diagnostics with the same problemText', () => {
+    const d1 = makeDiag({ from: 0, to: 8 });
+    const d2 = makeDiag({ from: 20, to: 28 });
+    const d3 = makeDiag({ from: 40, to: 48 });
+    const { view, getDispatched } = createMockView([d1, d2, d3]);
+
+    ignoreDiagnostic(view, d1);
+    expect(getDispatched()).toHaveLength(0);
+  });
+
+  it('removes same problemText across different lintKinds', () => {
+    const d1 = makeDiag({ from: 0, to: 8, lintKind: 'Spelling' });
+    const d2 = makeDiag({ from: 20, to: 28, lintKind: 'Style' });
+    const { view, getDispatched } = createMockView([d1, d2]);
+
+    ignoreDiagnostic(view, d1);
+    expect(getDispatched()).toHaveLength(0);
+  });
+
+  it('keeps diagnostics with different problemText', () => {
+    const d1 = makeDiag({ from: 0, to: 8, problemText: 'MarkEdit' });
+    const d2 = makeDiag({ from: 20, to: 25, problemText: 'other' });
+    const { view, getDispatched } = createMockView([d1, d2]);
+
+    ignoreDiagnostic(view, d1);
+    const remaining = getDispatched()!;
+    expect(remaining).toHaveLength(1);
+    expect(remaining[0].problemText).toBe('other');
+  });
+
+  it('falls back to positional match when problemText is empty', () => {
+    const d1 = makeDiag({ from: 0, to: 5, problemText: '', lintKind: 'Grammar' });
+    const d2 = makeDiag({ from: 10, to: 15, problemText: '', lintKind: 'Grammar' });
+    const { view, getDispatched } = createMockView([d1, d2]);
+
+    ignoreDiagnostic(view, d1);
+    const remaining = getDispatched()!;
+    expect(remaining).toHaveLength(1);
+    expect(remaining[0].from).toBe(10);
+  });
+});
 
 describe('cardContentCSS', () => {
   it('includes message, button, ignore, and actions styles', () => {