--- a/genshi/input.py
+++ b/genshi/input.py
@@ -349,8 +349,9 @@
         self._enqueue(TEXT, text)
 
     def handle_pi(self, data):
-        target, data = data.split(maxsplit=1)
-        data = data.rstrip('?')
+        target, data = data.split(None, 1)
+        if data.endswith('?'):
+            data = data[:-1]
         self._enqueue(PI, (target.strip(), data.strip()))
 
     def handle_comment(self, text):

--- a/genshi/tests/input.py
+++ b/genshi/tests/input.py
@@ -173,6 +173,22 @@
         self.assertEqual(Stream.TEXT, kind)
         self.assertEqual(u'\xa0', data)
 
+    def test_processing_instruction(self):
+        text = '<?php echo "Foobar" ?>'
+        events = list(HTMLParser(StringIO(text)))
+        kind, (target, data), pos = events[0]
+        self.assertEqual(Stream.PI, kind)
+        self.assertEqual(u'php', target)
+        self.assertEqual(u'echo "Foobar"', data)
+
+    def test_processing_instruction_trailing_qmark(self):
+        text = '<?php echo "Foobar" ??>'
+        events = list(HTMLParser(StringIO(text)))
+        kind, (target, data), pos = events[0]
+        self.assertEqual(Stream.PI, kind)
+        self.assertEqual(u'php', target)
+        self.assertEqual(u'echo "Foobar" ?', data)
+
 
 def suite():
     suite = unittest.TestSuite()