diff --git a/pyiceberg/avro/codecs/zstandard_codec.py b/pyiceberg/avro/codecs/zstandard_codec.py
index a048f68490..4cc815214f 100644
--- a/pyiceberg/avro/codecs/zstandard_codec.py
+++ b/pyiceberg/avro/codecs/zstandard_codec.py
@@ -39,7 +39,7 @@ def decompress(data: bytes) -> bytes:
                     if not chunk:
                         break
                     uncompressed.extend(chunk)
-            return uncompressed
+            return bytes(uncompressed)
 
 except ImportError:
 
diff --git a/tests/utils/test_manifest.py b/tests/utils/test_manifest.py
index c838c02ac6..825431c776 100644
--- a/tests/utils/test_manifest.py
+++ b/tests/utils/test_manifest.py
@@ -358,7 +358,7 @@ def test_write_empty_manifest() -> None:
 
 
 @pytest.mark.parametrize("format_version", [1, 2])
-@pytest.mark.parametrize("compression", ["null", "deflate"])
+@pytest.mark.parametrize("compression", ["null", "deflate", "zstd"])
 def test_write_manifest(
     generated_manifest_file_file_v1: str,
     generated_manifest_file_file_v2: str,