diff --git a/src/fonts.js b/src/fonts.js
index 0fe7f7508..de2f39cb7 100644
--- a/src/fonts.js
+++ b/src/fonts.js
@@ -441,6 +441,7 @@ var CMapConverterList = {
   '90msp-RKSJ-H': sjisToUnicode,
   '90msp-RKSJ-V': sjisToUnicode,
   'GBK-EUC-H': gbkToUnicode,
+  'GBKp-EUC-H': gbkToUnicode,
   'B5pc-H': big5ToUnicode,
   'ETenms-B5-H': big5ToUnicode,
   'ETenms-B5-V': big5ToUnicode,
diff --git a/test/pdfs/issue3521.pdf b/test/pdfs/issue3521.pdf
new file mode 100644
index 000000000..d03055cd5
Binary files /dev/null and b/test/pdfs/issue3521.pdf differ
diff --git a/test/test_manifest.json b/test/test_manifest.json
index 52d432a34..c25ed5a1c 100644
--- a/test/test_manifest.json
+++ b/test/test_manifest.json
@@ -1283,6 +1283,13 @@
       "rounds": 1,
       "type": "eq"
     },
+    {  "id": "issue3521.pdf",
+       "file": "pdfs/issue3521.pdf",
+       "md5": "df95d31443e20a38efa29c3a635a045b",
+       "rounds": 1,
+       "type": "eq",
+       "about": "Support for CMap GBKp-EUC-H"
+    },
     {  "id": "issue2829",
       "file": "pdfs/issue2829.pdf",
       "md5": "f32b28cf8792f6ccc470446bfbb38584",