diff --git a/src/ukify/ukify.py b/src/ukify/ukify.py
index c5cf21cde9..5bbe9b1ea6 100755
--- a/src/ukify/ukify.py
+++ b/src/ukify/ukify.py
@@ -183,20 +183,24 @@ def get_zboot_kernel(f: IO[bytes]) -> bytes:
     f.seek(start)
     if comp_type.startswith(b'gzip'):
         gzip = try_import('gzip')
-        return cast(bytes, gzip.open(f).read(size))
+        data = f.read(size)
+        return cast(bytes, gzip.decompress(data))
     elif comp_type.startswith(b'lz4'):
         lz4 = try_import('lz4.frame', 'lz4')
-        return cast(bytes, lz4.frame.decompress(f.read(size)))
+        data = f.read(size)
+        return cast(bytes, lz4.frame.decompress(data))
     elif comp_type.startswith(b'lzma'):
         lzma = try_import('lzma')
-        return cast(bytes, lzma.open(f).read(size))
+        data = f.read(size)
+        return cast(bytes, lzma.decompress(data))
     elif comp_type.startswith(b'lzo'):
         raise NotImplementedError('lzo decompression not implemented')
     elif comp_type.startswith(b'xzkern'):
         raise NotImplementedError('xzkern decompression not implemented')
     elif comp_type.startswith(b'zstd'):
         zstd = try_import('zstandard')
-        return cast(bytes, zstd.ZstdDecompressor().stream_reader(f.read(size)).read())
+        data = f.read(size)
+        return cast(bytes, zstd.ZstdDecompressor().stream_reader(data).read())
 
     raise NotImplementedError(f'unknown compressed type: {comp_type!r}')