diff --git a/examples/pdf-server/src/pdf-annotations.test.ts b/examples/pdf-server/src/pdf-annotations.test.ts
index fe34d835..d0fabcbb 100644
--- a/examples/pdf-server/src/pdf-annotations.test.ts
+++ b/examples/pdf-server/src/pdf-annotations.test.ts
@@ -460,7 +460,8 @@ describe("importPdfjsAnnotation", () => {
       annotationType: 9,
       ref: { num: 5, gen: 0 },
       rect: [72, 700, 272, 712],
-      quadPoints: [[72, 712, 272, 712, 72, 700, 272, 700]],
+      // pdf.js emits a FLAT Float32Array, not nested arrays.
+      quadPoints: new Float32Array([72, 712, 272, 712, 72, 700, 272, 700]),
       color: new Uint8ClampedArray([255, 255, 0]),
       contentsObj: { str: "Important" },
     };
@@ -474,12 +475,57 @@ describe("importPdfjsAnnotation", () => {
     expect((result as any).color).toBe("#ffff00");
   });
 
+  it("imports a multi-line highlight (multiple quads → multiple rects)", () => {
+    // Regression: the parser iterated quadPoints as if nested; pdf.js's
+    // flat array yielded numbers, so rects stayed empty and import bailed.
+    const ann = {
+      annotationType: 9,
+      ref: { num: 8, gen: 0 },
+      quadPoints: new Float32Array([
+        // line 1
+        72, 712, 272, 712, 72, 700, 272, 700,
+        // line 2
+        72, 698, 200, 698, 72, 686, 200, 686,
+      ]),
+      color: new Uint8ClampedArray([255, 255, 0]),
+    };
+    const result = importPdfjsAnnotation(ann, 1, 0);
+    expect(result).not.toBeNull();
+    expect(result!.type).toBe("highlight");
+    expect((result as any).rects).toHaveLength(2);
+    expect((result as any).rects[0]).toEqual({
+      x: 72,
+      y: 700,
+      width: 200,
+      height: 12,
+    });
+    expect((result as any).rects[1]).toEqual({
+      x: 72,
+      y: 686,
+      width: 128,
+      height: 12,
+    });
+  });
+
+  it("falls back to ann.rect when quadPoints is absent", () => {
+    const ann = {
+      annotationType: 9,
+      ref: { num: 9, gen: 0 },
+      rect: [72, 700, 272, 712],
+      color: new Uint8ClampedArray([255, 255, 0]),
+    };
+    const result = importPdfjsAnnotation(ann, 1, 0);
+    expect(result).not.toBeNull();
+    expect((result as any).rects).toHaveLength(1);
+  });
+
   it("imports an underline annotation", () => {
     const ann = {
       annotationType: 10,
       ref: { num: 6, gen: 0 },
       rect: [72, 700, 272, 712],
-      quadPoints: [[72, 712, 272, 712, 72, 700, 272, 700]],
+      // pdf.js emits a FLAT Float32Array, not nested arrays.
+      quadPoints: new Float32Array([72, 712, 272, 712, 72, 700, 272, 700]),
       color: new Uint8ClampedArray([255, 0, 0]),
     };
     const result = importPdfjsAnnotation(ann, 1, 0);
@@ -493,7 +539,8 @@ describe("importPdfjsAnnotation", () => {
       annotationType: 12,
       ref: { num: 7, gen: 0 },
       rect: [72, 700, 272, 712],
-      quadPoints: [[72, 712, 272, 712, 72, 700, 272, 700]],
+      // pdf.js emits a FLAT Float32Array, not nested arrays.
+      quadPoints: new Float32Array([72, 712, 272, 712, 72, 700, 272, 700]),
       color: new Uint8ClampedArray([255, 0, 0]),
     };
     const result = importPdfjsAnnotation(ann, 2, 0);
diff --git a/examples/pdf-server/src/pdf-annotations.ts b/examples/pdf-server/src/pdf-annotations.ts
index 25d9ebb6..6a7e268e 100644
--- a/examples/pdf-server/src/pdf-annotations.ts
+++ b/examples/pdf-server/src/pdf-annotations.ts
@@ -948,33 +948,28 @@ export function importPdfjsAnnotation(
     case "highlight":
     case "underline":
     case "strikethrough": {
-      // PDF.js provides quadPoints as array of arrays [[x1,y1,x2,y2,...], ...]
-      // or rect as [x1,y1,x2,y2]
-      let rects: Rect[];
-      if (ann.quadPoints && ann.quadPoints.length > 0) {
-        rects = [];
-        for (const qp of ann.quadPoints) {
-          // Each quadPoint is [x1,y1,x2,y2,x3,y3,x4,y4]
-          // We need the bounding box
-          if (qp.length >= 8) {
-            const xs = [qp[0], qp[2], qp[4], qp[6]];
-            const ys = [qp[1], qp[3], qp[5], qp[7]];
-            const minX = Math.min(...xs);
-            const minY = Math.min(...ys);
-            const maxX = Math.max(...xs);
-            const maxY = Math.max(...ys);
-            rects.push({
-              x: minX,
-              y: minY,
-              width: maxX - minX,
-              height: maxY - minY,
-            });
-          }
+      // pdf.js emits quadPoints as a FLAT Float32Array [x1,y1,...,x4,y4, …]
+      // (8 numbers per quad), NOT as nested arrays. Iterating it yields
+      // numbers, so the old `for (const qp of …) if (qp.length>=8)` never
+      // matched and every quad-based annotation was dropped (#506).
+      const rects: Rect[] = [];
+      const qp = ann.quadPoints as ArrayLike<number> | undefined;
+      if (qp && qp.length >= 8) {
+        for (let i = 0; i + 8 <= qp.length; i += 8) {
+          const xs = [qp[i], qp[i + 2], qp[i + 4], qp[i + 6]];
+          const ys = [qp[i + 1], qp[i + 3], qp[i + 5], qp[i + 7]];
+          const minX = Math.min(...xs);
+          const minY = Math.min(...ys);
+          rects.push({
+            x: minX,
+            y: minY,
+            width: Math.max(...xs) - minX,
+            height: Math.max(...ys) - minY,
+          });
         }
-      } else if (ann.rect) {
-        rects = [pdfjsRectToRect(ann.rect)];
-      } else {
-        return null;
+      }
+      if (rects.length === 0 && ann.rect) {
+        rects.push(pdfjsRectToRect(ann.rect));
       }
       if (rects.length === 0) return null;