diff --git a/test/integration/highlight_selection_spec.mjs b/test/integration/highlight_selection_spec.mjs
new file mode 100644
index 0000000000000..a32ad45d06d87
--- /dev/null
+++ b/test/integration/highlight_selection_spec.mjs
@@ -0,0 +1,58 @@
+/* Copyright 2024 Mozilla Foundation
+ *
+ * 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 { closePages, loadAndWait } from "./test_utils.mjs";
+
+describe("Highlight Selection", () => {
+  let pages;
+
+  beforeAll(async () => {
+    pages = await loadAndWait("issue18190.pdf", {
+      annotationMode: 1, // ENABLE
+    });
+  });
+
+  afterAll(async () => {
+    await closePages(pages);
+  });
+
+  it("must allow text selection under highlight annotation", async () => {
+    await Promise.all(
+      pages.map(async ([browserName, page]) => {
+        // Wait for annotations/text layer
+        await page.waitForSelector(".annotationLayer");
+        await page.waitForSelector(".textLayer");
+
+        // Coordinates of the highlighted text (approximate from PDF structure)
+        // We will simulate a drag to select text.
+        // Assuming the highlighted text is on the standard text layer.
+        // We verify pointer-events via evaluation if selection is flaky without
+        // exact coords.
+
+        // Check computed style.
+        const highlightStyle = await page.evaluate(() => {
+          const highlight = document.querySelector(".highlightAnnotation");
+          if (!highlight) {
+            return null;
+          }
+          return window.getComputedStyle(highlight).pointerEvents;
+        });
+
+        // The critical check: pointer-events must be 'none'
+        expect(highlightStyle).withContext(`In ${browserName}`).toBe("none");
+      })
+    );
+  });
+});
diff --git a/web/annotation_layer_builder.css b/web/annotation_layer_builder.css
index c1c2a8d54ce72..fb850174d7d3e 100644
--- a/web/annotation_layer_builder.css
+++ b/web/annotation_layer_builder.css
@@ -82,9 +82,11 @@
   &[data-main-rotation="90"] .norotate {
     transform: rotate(270deg) translateX(-100%);
   }
+
   &[data-main-rotation="180"] .norotate {
     transform: rotate(180deg) translate(-100%, -100%);
   }
+
   &[data-main-rotation="270"] .norotate {
     transform: rotate(90deg) translateY(-100%);
   }
@@ -174,6 +176,14 @@
     left: 0;
   }
 
+  .highlightAnnotation,
+  .underlineAnnotation,
+  .squigglyAnnotation,
+  .strikeoutAnnotation {
+    cursor: pointer;
+    pointer-events: none;
+  }
+
   .textWidgetAnnotation :is(input, textarea),
   .choiceWidgetAnnotation select,
   .buttonWidgetAnnotation:is(.checkBox, .radioButton) input {
@@ -218,6 +228,7 @@
   .buttonWidgetAnnotation:is(.checkBox, .radioButton) input:hover {
     border: 2px solid var(--input-hover-border-color);
   }
+
   .textWidgetAnnotation :is(input, textarea):hover,
   .choiceWidgetAnnotation select:hover,
   .buttonWidgetAnnotation.checkBox input:hover {