diff --git a/silo-import/pyproject.toml b/silo-import/pyproject.toml
index 4a5586fde1..a83aba8c51 100644
--- a/silo-import/pyproject.toml
+++ b/silo-import/pyproject.toml
@@ -5,6 +5,7 @@ requires-python = ">=3.11"
 dependencies = [
     "zstandard>=0.22,<0.26",
     "requests>=2.31,<3.0",
+    "orjsonl>=0.3,<1.0",
 ]
 
 [project.scripts]
diff --git a/silo-import/src/silo_import/decompressor.py b/silo-import/src/silo_import/decompressor.py
index ba2053757c..2ae80fdbdf 100644
--- a/silo-import/src/silo_import/decompressor.py
+++ b/silo-import/src/silo_import/decompressor.py
@@ -2,13 +2,11 @@
 
 from __future__ import annotations
 
-import io
-import json
 import logging
 from dataclasses import dataclass
 from pathlib import Path
 
-import zstandard
+import orjsonl
 
 logger = logging.getLogger(__name__)
 
@@ -18,7 +16,7 @@ class NdjsonAnalysis:
     """Result of analyzing an NDJSON file."""
 
     record_count: int
-    pipeline_versions: set[int]
+    pipeline_version: int | None
 
 
 def analyze_ndjson(path: Path) -> NdjsonAnalysis:
@@ -35,30 +33,17 @@ def analyze_ndjson(path: Path) -> NdjsonAnalysis:
         RuntimeError: If decompression or JSON parsing fails
     """
     record_count = 0
-    pipeline_versions: set[int] = set()
-    decompressor = zstandard.ZstdDecompressor()
+    pipeline_version: int | None = None
 
     try:
-        with path.open("rb") as compressed, decompressor.stream_reader(compressed) as reader:
-            text_stream = io.TextIOWrapper(reader, encoding="utf-8")
-            for line in text_stream:
-                line_stripped = line.strip()
-                if not line_stripped:
-                    continue
-                record_count += 1
-                try:
-                    obj = json.loads(line_stripped)
-                except json.JSONDecodeError as exc:
-                    msg = f"Invalid JSON record: {exc}"
-                    raise RuntimeError(msg) from exc
+        for record in orjsonl.stream(path):
+            record_count += 1
+            if pipeline_version is None:
+                pipeline_version = record.get("metadata", {}).get("pipelineVersion")  # type: ignore
 
-                metadata = obj.get("metadata") if isinstance(obj, dict) else None
-                if isinstance(metadata, dict):
-                    pipeline_version = metadata.get("pipelineVersion")
-                    if pipeline_version:
-                        pipeline_versions.add(int(pipeline_version))
-    except zstandard.ZstdError as exc:
+    except Exception as exc:
         msg = f"Failed to decompress {path}: {exc}"
+        logger.error(msg)
         raise RuntimeError(msg) from exc
 
-    return NdjsonAnalysis(record_count=record_count, pipeline_versions=pipeline_versions)
+    return NdjsonAnalysis(record_count=record_count, pipeline_version=pipeline_version)
diff --git a/silo-import/src/silo_import/download_manager.py b/silo-import/src/silo_import/download_manager.py
index 313e72b8fb..0df45cd9c1 100644
--- a/silo-import/src/silo_import/download_manager.py
+++ b/silo-import/src/silo_import/download_manager.py
@@ -45,7 +45,7 @@ class DownloadResult:
     directory: Path
     data_path: Path
     etag: str
-    pipeline_versions: set[int]
+    pipeline_version: int | None
 
 
 def _download_file(
@@ -202,7 +202,7 @@ def download_release(
                 directory=download_dir,
                 data_path=data_path,
                 etag=etag_value,
-                pipeline_versions=analysis.pipeline_versions,
+                pipeline_version=analysis.pipeline_version,
             )
 
         except (
diff --git a/silo-import/src/silo_import/lineage.py b/silo-import/src/silo_import/lineage.py
index bb4c5e55f4..35abbdd236 100644
--- a/silo-import/src/silo_import/lineage.py
+++ b/silo-import/src/silo_import/lineage.py
@@ -13,7 +13,7 @@
 
 
 def update_lineage_definitions(
-    pipeline_versions: set[int],
+    pipeline_version: int | None,
     config: ImporterConfig,
     paths: ImporterPaths,
 ) -> None:
@@ -21,17 +21,12 @@ def update_lineage_definitions(
         logger.info("LINEAGE_DEFINITIONS not provided; skipping lineage configuration")
         return
 
-    if not pipeline_versions:
+    if not pipeline_version:
         # required for dummy organisms
         logger.info("No pipeline version found; writing empty lineage definitions")
         write_text(paths.lineage_definition_file, "{}\n")
         return
 
-    if len(pipeline_versions) > 1:
-        msg = "Multiple pipeline versions found in released data"
-        raise RuntimeError(msg)
-
-    pipeline_version = next(iter(pipeline_versions))
     lineage_url: str | None = config.lineage_definitions.get(int(pipeline_version))
     if not lineage_url:
         msg = f"No lineage definition URL configured for pipeline version {pipeline_version}"
diff --git a/silo-import/src/silo_import/runner.py b/silo-import/src/silo_import/runner.py
index 818edf49e0..9bd35ab991 100644
--- a/silo-import/src/silo_import/runner.py
+++ b/silo-import/src/silo_import/runner.py
@@ -79,7 +79,7 @@ def run_once(self) -> None:
             return
 
         try:
-            update_lineage_definitions(download.pipeline_versions, self.config, self.paths)
+            update_lineage_definitions(download.pipeline_version, self.config, self.paths)
         except Exception:
             logger.exception("Failed to download lineage definitions; cleaning up input")
             safe_remove(self.paths.silo_input_data_path)