diff --git a/gpxpy/parser.py b/gpxpy/parser.py
index 70b496a..04b2f5c 100644
--- a/gpxpy/parser.py
+++ b/gpxpy/parser.py
@@ -19,12 +19,21 @@
 
 try:
     # Load LXML or fallback to cET or ET
-    import lxml.etree as mod_etree # type: ignore
+    import lxml.etree as mod_lxml_etree # type: ignore
 except ImportError:
-    try:
-        import xml.etree.cElementTree as mod_etree # type: ignore
-    except ImportError:
-        import xml.etree.ElementTree as mod_etree # type: ignore
+    pass
+
+try:
+    import xml.etree.cElementTree as mod_xml_etree # type: ignore
+except ImportError:
+    import xml.etree.ElementTree as mod_xml_etree # type: ignore
+
+mod_etree = mod_xml_etree
+
+""" Change the etree implementation, use gpx.set_xml_etree(mod_lxml_etree) for lxml """
+def set_xml_etree(etre):
+    global mod_etree
+    mod_etree = etre
 
 from . import gpx as mod_gpx
 from . import utils as mod_utils
@@ -32,6 +41,7 @@
 
 log = mod_logging.getLogger(__name__)
 
+
 def library() -> str:
     """
     Return the underlying ETree.