diff --git a/packages/core-components/src/components/LogViewer/useLogViewerSelection.test.tsx b/packages/core-components/src/components/LogViewer/useLogViewerSelection.test.tsx
new file mode 100644
index 0000000000..7e00d50f33
--- /dev/null
+++ b/packages/core-components/src/components/LogViewer/useLogViewerSelection.test.tsx
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import React from 'react';
+import { act, renderHook } from '@testing-library/react-hooks';
+import { TestApiProvider, MockErrorApi } from '@backstage/test-utils';
+import { errorApiRef } from '@backstage/core-plugin-api';
+import { AnsiLine } from './AnsiProcessor';
+import { useLogViewerSelection } from './useLogViewerSelection';
+// eslint-disable-next-line import/no-extraneous-dependencies
+import copyToClipboard from 'copy-to-clipboard';
+
+// Used by useCopyToClipboard
+jest.mock('copy-to-clipboard', () => ({
+  __esModule: true,
+  default: jest.fn(),
+}));
+
+const lines = [
+  new AnsiLine(1, [{ text: '1', modifiers: {} }]),
+  new AnsiLine(2, [{ text: '2', modifiers: {} }]),
+  new AnsiLine(3, [{ text: '3', modifiers: {} }]),
+  new AnsiLine(4, [{ text: '4', modifiers: {} }]),
+  new AnsiLine(5, [{ text: '5', modifiers: {} }]),
+];
+
+describe('useLogViewerSelection', () => {
+  it('should manage a selection', () => {
+    const rendered = renderHook(() => useLogViewerSelection(lines), {
+      wrapper: ({ children }) => (
+        <TestApiProvider apis={[[errorApiRef, new MockErrorApi()]]}>
+          {children}
+        </TestApiProvider>
+      ),
+    });
+
+    expect(rendered.result.current.isSelected(1)).toBe(false);
+    expect(rendered.result.current.isSelected(2)).toBe(false);
+    expect(rendered.result.current.isSelected(3)).toBe(false);
+
+    expect(rendered.result.current.shouldShowButton(1)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(2)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(3)).toBe(false);
+
+    act(() => rendered.result.current.setSelection(2, false));
+
+    expect(rendered.result.current.isSelected(1)).toBe(false);
+    expect(rendered.result.current.isSelected(2)).toBe(true);
+    expect(rendered.result.current.isSelected(3)).toBe(false);
+
+    expect(rendered.result.current.shouldShowButton(1)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(2)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(3)).toBe(false);
+
+    act(() => rendered.result.current.setSelection(3, false));
+
+    expect(rendered.result.current.isSelected(1)).toBe(false);
+    expect(rendered.result.current.isSelected(2)).toBe(false);
+    expect(rendered.result.current.isSelected(3)).toBe(true);
+    expect(rendered.result.current.isSelected(4)).toBe(false);
+
+    expect(rendered.result.current.shouldShowButton(1)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(2)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(3)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(4)).toBe(false);
+
+    act(() => rendered.result.current.setSelection(1, true));
+
+    expect(rendered.result.current.isSelected(1)).toBe(true);
+    expect(rendered.result.current.isSelected(2)).toBe(true);
+    expect(rendered.result.current.isSelected(3)).toBe(true);
+    expect(rendered.result.current.isSelected(4)).toBe(false);
+
+    expect(rendered.result.current.shouldShowButton(1)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(2)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(3)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(4)).toBe(false);
+
+    act(() => rendered.result.current.setSelection(4, true));
+
+    expect(rendered.result.current.isSelected(1)).toBe(false);
+    expect(rendered.result.current.isSelected(2)).toBe(false);
+    expect(rendered.result.current.isSelected(3)).toBe(true);
+    expect(rendered.result.current.isSelected(4)).toBe(true);
+    expect(rendered.result.current.isSelected(5)).toBe(false);
+
+    expect(rendered.result.current.shouldShowButton(1)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(2)).toBe(false);
+    expect(rendered.result.current.shouldShowButton(3)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(4)).toBe(true);
+    expect(rendered.result.current.shouldShowButton(5)).toBe(false);
+
+    expect(copyToClipboard).not.toHaveBeenCalled();
+    act(() => rendered.result.current.copySelection());
+    expect(copyToClipboard).toHaveBeenLastCalledWith('3\n4');
+
+    act(() => rendered.result.current.setSelection(2, true));
+    act(() => rendered.result.current.setSelection(4, true));
+
+    act(() => rendered.result.current.copySelection());
+    expect(copyToClipboard).toHaveBeenCalledWith('2\n3\n4');
+
+    act(() => rendered.result.current.setSelection(2, false));
+    act(() => rendered.result.current.setSelection(4, false));
+    act(() => rendered.result.current.setSelection(4, false));
+    act(() => rendered.result.current.setSelection(5, true));
+    act(() => rendered.result.current.copySelection());
+    expect(copyToClipboard).toHaveBeenCalledWith('5');
+  });
+});
diff --git a/packages/core-components/src/components/LogViewer/useLogViewerSelection.tsx b/packages/core-components/src/components/LogViewer/useLogViewerSelection.tsx
index cae56e5e43..3bed43d0c5 100644
--- a/packages/core-components/src/components/LogViewer/useLogViewerSelection.tsx
+++ b/packages/core-components/src/components/LogViewer/useLogViewerSelection.tsx
@@ -59,7 +59,7 @@ export function useLogViewerSelection(lines: AnsiLine[]) {
     copySelection() {
       if (sel) {
         const copyText = lines
-          .slice(sel.start - 1, sel.end)
+          .slice(Math.min(sel.start, sel.end) - 1, Math.max(sel.start, sel.end))
           .map(l => l.text)
           .join('\n');
         copyToClipboard(copyText);