diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 8eb80f8..ef316b5 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -400,7 +400,7 @@
             except ImportError:
                 raise CompressionError("zlib module is not available")
             self.zlib = zlib
-            self.crc = zlib.crc32("")
+            self.crc = zlib.crc32(b"")
             if mode == "r":
                 self._init_read_gz()
             else: