diff --git a/dfvfs/file_io/apm_file_io.py b/dfvfs/file_io/apm_file_io.py
index 962bd58b..16b6981e 100644
--- a/dfvfs/file_io/apm_file_io.py
+++ b/dfvfs/file_io/apm_file_io.py
@@ -59,10 +59,6 @@ def _Open(self, mode='rb'):
         self._path_spec, resolver_context=self._resolver_context)
     vsapm_volume = self._file_system.GetAPMVolume()
 
-    if 0 < entry_index or entry_index >= vsapm_volume.number_of_partitions:
-      raise errors.PathSpecError(
-          f'Missing APM partition with entry index: {entry_index:d}')
-
     self._vsapm_partition = vsapm_volume.get_partition(entry_index)
 
     # Note that using pass-through IO in Python is faster than using