diff --git a/openedxscorm/scormxblock.py b/openedxscorm/scormxblock.py
index f94a085..16cd44f 100644
--- a/openedxscorm/scormxblock.py
+++ b/openedxscorm/scormxblock.py
@@ -42,6 +42,7 @@ def _(text):
 
 
 logger = logging.getLogger(__name__)
+OS_PATH_ALT_SEP = '\\'
 
 
 @XBlock.wants("settings")
@@ -384,7 +385,9 @@ def extract_package(self, package_file):
                     # the is_dir() method to verify whether a ZipInfo object points to a
                     # directory.
                     # https://docs.python.org/3.6/library/zipfile.html#zipfile.ZipInfo.is_dir
-                    if not zipinfo.filename.endswith("/"):
+                    # TODO: remove backported 'is_dir' method once upgraded to 
+                    # python 3.12.3 or greater. 
+                    if not is_dir(zipinfo):
                         dest_path = os.path.join(
                             self.extract_folder_path,
                             os.path.relpath(zipinfo.filename, root_path),
@@ -943,5 +946,18 @@ def parse_validate_positive_float(value, name):
     return parsed
 
 
+def is_dir(zipinfo):
+    """Return True if this archive member is a directory."""
+    if zipinfo.filename.endswith('/'):
+        return True
+    elif zipinfo.filename.endswith((os.path.sep, OS_PATH_ALT_SEP)):
+        # The ZIP format specification requires to use forward slashes
+        # as the directory separator, but in practice some ZIP files
+        # created on Windows can use backward slashes.  For compatibility
+        # with the extraction code which already handles this:
+        return True
+    return False 
+
+
 class ScormError(Exception):
     pass