diff --git a/blender_asset_tracer/blendfile/__init__.py b/blender_asset_tracer/blendfile/__init__.py
index 1b5a8b3..bf3b61c 100644
--- a/blender_asset_tracer/blendfile/__init__.py
+++ b/blender_asset_tracer/blendfile/__init__.py
@@ -20,6 +20,7 @@
 # (c) 2014, Blender Foundation - Campbell Barton
 # (c) 2018, Blender Foundation - Sybren A. Stüvel
 
+import atexit
 import collections
 import gzip
 import logging
@@ -27,6 +28,8 @@ import os
 import struct
 import pathlib
 import tempfile
+
+import functools
 import typing
 
 from . import exceptions, dna_io, dna, header
@@ -39,6 +42,29 @@ FILE_BUFFER_SIZE = 1024 * 1024
 BLENDFILE_MAGIC = b'BLENDER'
 GZIP_MAGIC = b'\x1f\x8b'
 
+_cached_bfiles = {}
+
+
+def open_cached(path: pathlib.Path, mode='rb') -> 'BlendFile':
+    """Open a blend file, ensuring it is only opened once."""
+    bfile_path = path.absolute().resolve()
+    try:
+        return _cached_bfiles[bfile_path]
+    except KeyError:
+        pass
+
+    bfile = BlendFile(path, mode=mode)
+    _cached_bfiles[bfile_path] = bfile
+    return bfile
+
+
+@atexit.register
+def close_all_cached():
+    log.info('Closing all blend files')
+    for bfile in _cached_bfiles.values():
+        bfile.close()
+    _cached_bfiles.clear()
+
 
 class BlendFile:
     """Representation of a blend file.
diff --git a/blender_asset_tracer/tracer/__init__.py b/blender_asset_tracer/tracer/__init__.py
index 366aec7..f27ad57 100644
--- a/blender_asset_tracer/tracer/__init__.py
+++ b/blender_asset_tracer/tracer/__init__.py
@@ -23,9 +23,9 @@ def deps(bfilepath: pathlib.Path) -> typing.Iterator[result.BlockUsage]:
     :param bfilepath: File to open.
     """
 
-    with blendfile.BlendFile(bfilepath) as bfile:
-        for block in asset_holding_blocks(file2blocks.iter_blocks(bfile)):
-            yield from blocks2assets.iter_assets(block)
+    bfile = blendfile.open_cached(bfilepath)
+    for block in asset_holding_blocks(file2blocks.iter_blocks(bfile)):
+        yield from blocks2assets.iter_assets(block)
 
 
 def asset_holding_blocks(blocks: typing.Iterable[blendfile.BlendFileBlock]) \
diff --git a/blender_asset_tracer/tracer/file2blocks.py b/blender_asset_tracer/tracer/file2blocks.py
index 283f720..a9b7bba 100644
--- a/blender_asset_tracer/tracer/file2blocks.py
+++ b/blender_asset_tracer/tracer/file2blocks.py
@@ -86,9 +86,8 @@ class _BlockIterator:
                 continue
 
             log.debug('Expanding %d blocks in %s', len(idblocks), lib_path)
-
-            with blendfile.BlendFile(lib_path) as libfile:
-                yield from self.iter_blocks(libfile, idblocks)
+            libfile = blendfile.open_cached(lib_path)
+            yield from self.iter_blocks(libfile, idblocks)
 
     def _queue_all_blocks(self, bfile: blendfile.BlendFile):
         log.debug('Queueing all blocks from file %s', bfile.filepath)