diff --git a/suite/regress/x64_bigint.py b/suite/regress/x64_bigint.py
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+++ b/suite/regress/x64_bigint.py
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+#!/usr/bin/python
+# example on how to code a Keystone regression in Python
+# Nguyen Anh Quynh, 2016
+
+# Fill in the information in the form below when you create a new regression
+
+# Github issue: #12
+# Author: Nguyen Anh Quynh
+
+from keystone import *
+
+import regress
+
+class TestX86(regress.RegressTest):
+    def runTest(self):
+        # Initialize Keystone engine
+        ks = Ks(KS_ARCH_X86, KS_MODE_64)
+        # Assemble to get back insn encoding & statement count
+        encoding, count = ks.asm("mov rdi, 0x1122334455")
+        # Assert the result
+        self.assertEqual(encoding, [ 0x48, 0xBF, 0x55, 0x44, 0x33, 0x22, 0x11, 0x00, 0x00, 0x00 ])
+
+if __name__ == '__main__':
+    regress.main()