diff --git a/src/core/fonts.js b/src/core/fonts.js
index 677e29386..b173e02eb 100644
--- a/src/core/fonts.js
+++ b/src/core/fonts.js
@@ -2475,6 +2475,12 @@ var Font = (function FontClosure() {
         for (var code in GlyphMapForStandardFonts) {
           map[+code] = GlyphMapForStandardFonts[code];
         }
+        var isIdentityUnicode = this.toUnicode instanceof IdentityToUnicodeMap;
+        if (!isIdentityUnicode) {
+          this.toUnicode.forEach(function(charCode, unicodeCharCode) {
+            map[+charCode] = unicodeCharCode;
+          });
+        }
         this.toFontChar = map;
         this.toUnicode = new ToUnicodeMap(map);
       } else if (/Symbol/i.test(fontName)) {
diff --git a/test/pdfs/.gitignore b/test/pdfs/.gitignore
index 8edc0bd67..2e34a2b7c 100644
--- a/test/pdfs/.gitignore
+++ b/test/pdfs/.gitignore
@@ -59,6 +59,7 @@
 !bug864847.pdf
 !issue1002.pdf
 !issue925.pdf
+!issue2840.pdf
 !issue4668.pdf
 !issue5039.pdf
 !issue5070.pdf
diff --git a/test/pdfs/issue2840.pdf b/test/pdfs/issue2840.pdf
new file mode 100644
index 000000000..b623fe7da
--- /dev/null
+++ b/test/pdfs/issue2840.pdf
@@ -0,0 +1,128 @@
+%PDF-1.7
+28 0 obj
+<<
+/Type /Catalog
+/Pages 29 0 R
+>>
+endobj
+29 0 obj
+<<
+/Type /Pages
+/MediaBox [ 0 0 200 50 ]
+/Count 1
+/Kids [ 30 0 R ]
+>>
+endobj
+30 0 obj
+<<
+/Type /Page
+/Parent 29 0 R
+/Resources <<
+/Font <<
+/F1 31 0 R
+>>
+
+>>
+
+/Contents 32 0 R
+>>
+endobj
+31 0 obj
+<<
+/Type /Font
+/Subtype /Type0
+/BaseFont /Arial,Bold
+/Encoding /Identity-H
+/DescendantFonts [ 13 0 R ]
+/ToUnicode 11 0 R
+>>
+endobj
+32 0 obj
+<<
+/Length 79
+>>
+stream
+BT
+10 20 TD
+/F1 20 Tf
+<024702680266025F026A00030269026802650262026B025A> Tj
+ET
+endstream
+endobj
+13 0 obj
+<<
+/Type /Font
+/Subtype /CIDFontType2
+/BaseFont /Arial,Bold
+/CIDSystemInfo 12 0 R
+/FontDescriptor 10 0 R
+/W [ 587 [ 722 ] 588 [ 611 ] 586 [ 667 ] 570 [ 722 ] 591 [ 667 ] 584 [ 778 ] 572 [ 722 ] 583 [ 722 ] 578 [ 719 ] 601 [ 719 ] 3 [ 278 ] 582 [ 833 ] 575 [ 667 ] 574 [ 712 ] 592 [ 730 ] 580 [ 610 ] 597 [ 979 ] 585 [ 719 ] 581 [ 702 ] 195 [ 278 ] 577 [ 626 ] 576 [ 904 ] 600 [ 1031 ] 595 [ 1019 ] 573 [ 567 ] 11 [ 333 ] 571 [ 719 ] 579 [ 719 ] 12 [ 333 ] 616 [ 611 ] 614 [ 740 ] 607 [ 556 ] 618 [ 611 ] 617 [ 604 ] 613 [ 635 ] 610 [ 615 ] 619 [ 556 ] 602 [ 556 ] 46 [ 722 ] 53 [ 722 ] 56 [ 722 ] 38 [ 722 ] 43 [ 722 ] 40 [ 667 ] 49 [ 722 ] 50 [ 778 ] 15 [ 278 ] 39 [ 722 ] 48 [ 833 ] 44 [ 278 ] 55 [ 611 ] 60 [ 667 ] 620 [ 490 ] 623 [ 556 ] 604 [ 615 ] 630 [ 615 ] 18 [ 278 ] 615 [ 604 ] 629 [ 854 ] 611 [ 615 ] 51 [ 667 ] 82 [ 611 ] 79 [ 278 ] 76 [ 278 ] 70 [ 556 ] 92 [ 556 ] 75 [ 611 ] 71 [ 611 ] 72 [ 556 ] 85 [ 389 ] 81 [ 611 ] 86 [ 556 ] 88 [ 611 ] 83 [ 611 ] 633 [ 583 ] 42 [ 778 ] 74 [ 611 ] 68 [ 556 ] 47 [ 611 ] 80 [ 889 ] 87 [ 333 ] 612 [ 500 ] 609 [ 497 ] 606 [ 635 ] 73 [ 333 ] 77 [ 278 ] 36 [ 722 ] 19 [ 556 ] 22 [ 556 ] 17 [ 278 ] 21 [ 556 ] 20 [ 556 ] 608 [ 709 ] 621 [ 556 ] 28 [ 556 ] 23 [ 556 ] 27 [ 556 ] 24 [ 556 ] 7 [ 556 ] 37 [ 722 ] 54 [ 667 ] 16 [ 333 ] 624 [ 615 ] 9 [ 722 ] 91 [ 556 ] 625 [ 581 ] 69 [ 611 ] 603 [ 618 ] 626 [ 833 ] 78 [ 556 ] 89 [ 556 ] 605 [ 417 ] 29 [ 333 ] 26 [ 556 ] 25 [ 556 ] 622 [ 875 ] 35 [ 975 ] 30 [ 333 ] 90 [ 778 ] 598 [ 719 ] 589 [ 622 ] 14 [ 584 ] ]
+>>
+endobj
+11 0 obj
+<<
+/Length 929
+/Filter /FlateDecode
+/Length1 2189
+>>
+stream
+x
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�?>7�~l���~����=�>���/�
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+endobj
+12 0 obj
+<<
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+/Supplement 0
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+10 0 obj
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+/FontName /Arial,Bold
+/FontFamily /Arial,Bold
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+/ItalicAngle 0
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+/Descent -210
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+/StemV 166
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+/MxWidth 2628
+/MissingWidth 479
+>>
+endobj
+xref
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+trailer
+<<
+/Size 9
+/Root 28 0 R
+>>
+startxref
+3402
+%%EOF
\ No newline at end of file
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 65c145d65..45de838d2 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -746,6 +746,13 @@
        "type": "eq",
        "about": "Seac with differences array that messes up mapping."
     },
+    {  "id": "issue2840",
+       "file": "pdfs/issue2840.pdf",
+       "md5": "d9df49f6d62668d099e0fb7e74f8f337",
+       "rounds": 1,
+       "link": false,
+       "type": "eq"
+    },
     {  "id": "bug866395",
        "file": "pdfs/bug866395.pdf",
        "md5": "f03bc77e84637241980b09a0a220f575",