diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 65c99f1..422600a 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -214,6 +214,21 @@ def check_encoding(ET, encoding):
     """
     ET.XML("<?xml version='1.0' encoding='%s'?><xml />" % encoding)
 
+def processinginstruction():
+    """
+    Test ProcessingInstruction directly
+
+    >>> from xml.etree import ElementTree as ET
+
+    >>> ET.tostring(ET.ProcessingInstruction('test', 'instruction'))
+    '<?test instruction?>'
+    >>> ET.tostring(ET.PI('test', 'instruction'))
+    '<?test instruction?>'
+
+    Issue #2746
+
+    >>> ET.tostring(ET.PI('test', '<testing&>'))
+    '<?test <testing&>?>'
+
+    """
 
 #
 # xinclude tests (samples from appendix C of the xinclude specification)
diff --git a/Lib/xml/etree/ElementTree.py b/Lib/xml/etree/ElementTree.py
index 7dbc72e..e5afcbc 100644
--- a/Lib/xml/etree/ElementTree.py
+++ b/Lib/xml/etree/ElementTree.py
@@ -666,9 +666,9 @@ class ElementTree:
         # write XML to file
         tag = node.tag
         if tag is Comment:
-            file.write("<!-- %s -->" % _escape_cdata(node.text, encoding))
+            file.write("<!-- %s -->" % _encode(node.text, encoding))
         elif tag is ProcessingInstruction:
-            file.write("<?%s?>" % _escape_cdata(node.text, encoding))
+            file.write("<?%s?>" % _encode(node.text, encoding))
         else:
             items = node.items()
             xmlns_items = [] # new namespaces in this scope