diff --git a/test/integration-boot.js b/test/integration-boot.js
index 7749c6681..7abedb82d 100644
--- a/test/integration-boot.js
+++ b/test/integration-boot.js
@@ -28,6 +28,7 @@ async function runTests(results) {
       "scripting_spec.js",
       "annotation_spec.js",
       "accessibility_spec.js",
+      "find_spec.js",
     ],
   });
 
diff --git a/test/integration/find_spec.js b/test/integration/find_spec.js
new file mode 100644
index 000000000..93166bba1
--- /dev/null
+++ b/test/integration/find_spec.js
@@ -0,0 +1,75 @@
+/* Copyright 2021 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.
+ */
+
+const { closePages, loadAndWait } = require("./test_utils.js");
+
+function fuzzyMatch(a, b, browserName, pixelFuzz = 3) {
+  expect(a)
+    .withContext(`In ${browserName}`)
+    .toBeLessThan(b + pixelFuzz);
+  expect(a)
+    .withContext(`In ${browserName}`)
+    .toBeGreaterThan(b - pixelFuzz);
+}
+
+describe("find bar", () => {
+  describe("highlight all", () => {
+    let pages;
+
+    beforeAll(async () => {
+      pages = await loadAndWait("find_all.pdf#zoom=100", ".textLayer");
+    });
+
+    afterAll(async () => {
+      await closePages(pages);
+    });
+
+    it("must highlight text in the right position", async () => {
+      await Promise.all(
+        pages.map(async ([browserName, page]) => {
+          await page.click("#viewFind");
+          await page.waitForSelector("#viewFind", { hidden: false });
+          await page.type("#findInput", "a");
+          await page.click("#findHighlightAll");
+          await page.waitForSelector(".textLayer .highlight");
+          // The PDF has the text "AB BA" in a monospace font.
+          // Make sure we have the right number of highlighted divs.
+          const highlights = await page.$$(".textLayer .highlight");
+          expect(highlights.length).withContext(`In ${browserName}`).toEqual(2);
+          const glyphWidth = 15.98; // From the PDF.
+          const pageDiv = await page.$(".page canvas");
+          const pageBox = await pageDiv.boundingBox();
+          const firstA = await highlights[0].boundingBox();
+          const secondA = await highlights[1].boundingBox();
+          // Subtract the page offset from the text bounding boxes;
+          firstA.x = firstA.x - pageBox.x;
+          firstA.y = firstA.y - pageBox.y;
+          secondA.x = secondA.x - pageBox.x;
+          secondA.y = secondA.y - pageBox.y;
+          // They should be on the same line.
+          expect(firstA.y).withContext(`In ${browserName}`).toEqual(secondA.y);
+          const fontSize = 26.66; // From the PDF.
+          // The highlighted text has more padding.
+          fuzzyMatch(firstA.height, fontSize + 5, browserName);
+          fuzzyMatch(secondA.height, fontSize + 5, browserName);
+          const expectedFirstAX = 28;
+          fuzzyMatch(firstA.x, expectedFirstAX, browserName);
+          // The second 'A' should be 4 glyphs widths from the first.
+          fuzzyMatch(secondA.x, expectedFirstAX + glyphWidth * 4, browserName);
+        })
+      );
+    });
+  });
+});
diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
index d3498e1c5..6915b4600 100644
--- a/test/pdfs/.gitignore
+++ b/test/pdfs/.gitignore
@@ -247,6 +247,7 @@
 !S2.pdf
 !glyph_accent.pdf
 !personwithdog.pdf
+!find_all.pdf
 !helloworld-bad.pdf
 !zerowidthline.pdf
 !js-colors.pdf
diff --git a/test/pdfs/find_all.pdf b/test/pdfs/find_all.pdf
new file mode 100644
index 000000000..7379e3f93
Binary files /dev/null and b/test/pdfs/find_all.pdf differ
diff --git a/web/text_layer_builder.css b/web/text_layer_builder.css
index 1d453b16e..1dc915544 100644
--- a/web/text_layer_builder.css
+++ b/web/text_layer_builder.css
@@ -33,6 +33,7 @@
 }
 
 .textLayer .highlight {
+  position: relative;
   margin: -1px;
   padding: 1px;
   background-color: rgba(180, 0, 170, 1);