diff --git a/parso/python/diff.py b/parso/python/diff.py
index cda422a..719f3ed 100644
--- a/parso/python/diff.py
+++ b/parso/python/diff.py
@@ -19,6 +19,8 @@ from parso.python.token import PythonTokenTypes
 LOG = logging.getLogger(__name__)
 DEBUG_DIFF_PARSER = False
 
+_INDENTATION_TOKENS = 'INDENT', 'ERROR_DEDENT', 'DEDENT'
+
 
 def _assert_valid_graph(node):
     """
@@ -33,11 +35,12 @@ def _assert_valid_graph(node):
 
         # Ignore INDENT is necessary, because indent/dedent tokens don't
         # contain value/prefix and are just around, because of the tokenizer.
-        error_tokens = 'INDENT', 'ERROR_DEDENT', 'DEDENT'
-        if node.type == 'error_leaf' and node.token_type in error_tokens:
+        if node.type == 'error_leaf' and node.token_type in _INDENTATION_TOKENS:
+            assert not node.value
+            assert not node.prefix
             return
         while previous_leaf and previous_leaf.type == 'error_leaf' \
-                and previous_leaf.token_type in error_tokens:
+                and previous_leaf.token_type in _INDENTATION_TOKENS:
             assert previous_leaf.end_pos <= node.start_pos, \
                 (previous_leaf, node)
             previous_leaf = previous_leaf.get_previous_leaf()
@@ -428,6 +431,11 @@ class _NodesTreeNode(object):
         children = []
         for prefix, children_part, line_offset, last_line_offset_leaf in self._children_groups:
             first_leaf = children_part[0].get_first_leaf()
+
+            while first_leaf.type == 'error_leaf' \
+                    and first_leaf.token_type in _INDENTATION_TOKENS:
+                first_leaf = first_leaf.get_next_leaf()
+
             first_leaf.prefix = prefix + first_leaf.prefix
             if line_offset != 0:
                 try:
diff --git a/parso/python/tree.py b/parso/python/tree.py
index 3e26b00..a3d8338 100644
--- a/parso/python/tree.py
+++ b/parso/python/tree.py
@@ -169,7 +169,9 @@ class EndMarker(_LeafWithoutNewlines):
 
     @utf8_repr
     def __repr__(self):
-        return "<%s: prefix=%s>" % (type(self).__name__, repr(self.prefix))
+        return "<%s: prefix=%s end_pos=%s>" % (
+            type(self).__name__, repr(self.prefix), self.end_pos
+        )
 
 
 class Newline(PythonLeaf):
diff --git a/test/test_diff_parser.py b/test/test_diff_parser.py
index 53fa79f..7121e70 100644
--- a/test/test_diff_parser.py
+++ b/test/test_diff_parser.py
@@ -1069,3 +1069,31 @@ def test_opening_bracket_at_end(differ):
     differ.initialize(code1)
     differ.parse(code2, copies=1, parsers=2, expect_error_leaves=True)
     differ.parse(code1, copies=1, parsers=1, expect_error_leaves=True)
+
+
+def test_all_sorts_of_indentation(differ):
+    code1 = dedent('''\
+        class C:
+            1
+            def f():
+                    'same'
+
+                    if foo:
+                        a = b
+                end
+        ''')
+    code2 = dedent('''\
+        class C:
+            1
+            def f(yield await %|(
+                    'same'
+
+          \x02\x06\x0f\x1c\x11
+                    if foo:
+                        a = b
+
+                end
+        ''')
+    differ.initialize(code1)
+    differ.parse(code2, copies=2, parsers=3, expect_error_leaves=True)
+    differ.parse(code1, copies=1, parsers=3)