diff --git a/parso/python/diff.py b/parso/python/diff.py
index d69d0c5..ae2832c 100644
--- a/parso/python/diff.py
+++ b/parso/python/diff.py
@@ -602,7 +602,8 @@ class _NodesTree(object):
         is_endmarker = last_leaf.type == 'endmarker'
         self._prefix_remainder = ''
         if is_endmarker:
-            separation = max(last_leaf.prefix.rfind('\n'), last_leaf.prefix.rfind('\r'))
+            prefix = last_leaf.prefix
+            separation = max(prefix.rfind('\n'), prefix.rfind('\r'))
             if separation > -1:
                 # Remove the whitespace part of the prefix after a newline.
                 # That is not relevant if parentheses were opened. Always parse
diff --git a/parso/python/tokenize.py b/parso/python/tokenize.py
index ebb2c43..f490bb0 100644
--- a/parso/python/tokenize.py
+++ b/parso/python/tokenize.py
@@ -522,12 +522,7 @@ def tokenize_lines(lines, version_info, start_pos=(1, 0), indents=None):
             if new_line and initial not in '\r\n#' and (initial != '\\' or pseudomatch is None):
                 new_line = False
                 if paren_level == 0 and not fstring_stack:
-                    i = 0
                     indent_start = start
-                    while line[i] == '\f':
-                        i += 1
-                        # TODO don't we need to change spos as well?
-                        indent_start -= 1
                     if indent_start > indents[-1]:
                         yield PythonToken(INDENT, '', spos, '')
                         indents.append(indent_start)
diff --git a/test/test_diff_parser.py b/test/test_diff_parser.py
index e1cb51e..ae65980 100644
--- a/test/test_diff_parser.py
+++ b/test/test_diff_parser.py
@@ -1406,3 +1406,24 @@ def test_error_dedent_in_function(differ):
         ''')
     differ.initialize(code1)
     differ.parse(code2, parsers=ANY, copies=ANY, expect_error_leaves=True)
+
+
+def test_x(differ):
+    code1 = dedent('''\
+        @bla
+        async def foo():
+            1
+            yield from []
+            return
+            return ''
+        ''')
+    code2 = dedent('''\
+        @bla
+        async def foo():
+            1
+        \x0cimport 
+            return
+            return ''
+        ''')
+    differ.initialize(code1)
+    differ.parse(code2, parsers=ANY, copies=ANY, expect_error_leaves=True)
diff --git a/test/test_pgen2.py b/test/test_pgen2.py
index 30b0c23..4a80922 100644
--- a/test/test_pgen2.py
+++ b/test/test_pgen2.py
@@ -29,13 +29,17 @@ def _invalid_syntax(code, version=None, **kwargs):
         print(module.children)
 
 
-def test_formfeed(each_py2_version):
-    s = u"""print 1\n\x0Cprint 2\n"""
-    t = _parse(s, each_py2_version)
-    assert t.children[0].children[0].type == 'print_stmt'
-    assert t.children[1].children[0].type == 'print_stmt'
-    s = u"""1\n\x0C\x0C2\n"""
-    t = _parse(s, each_py2_version)
+def test_formfeed(each_version):
+    s = u"foo\n\x0c\nfoo\n"
+    t = _parse(s, each_version)
+    assert t.children[0].children[0].type == 'name'
+    assert t.children[1].children[0].type == 'name'
+    s = u"1\n\x0c\x0c\n2\n"
+    t = _parse(s, each_version)
+
+    with pytest.raises(ParserSyntaxError):
+        s = u"\n\x0c2\n"
+        _parse(s, each_version)
 
 
 def test_matrix_multiplication_operator(works_ge_py35):
diff --git a/test/test_tokenize.py b/test/test_tokenize.py
index ff396a6..e8500ca 100644
--- a/test/test_tokenize.py
+++ b/test/test_tokenize.py
@@ -332,11 +332,13 @@ def test_brackets_no_indentation():
 
 
 def test_form_feed():
-    error_token, endmarker = _get_token_list(dedent('''\
+    indent, error_token, dedent_, endmarker = _get_token_list(dedent('''\
         \f"""'''))
     assert error_token.prefix == '\f'
     assert error_token.string == '"""'
     assert endmarker.prefix == ''
+    assert indent.type == INDENT
+    assert dedent_.type == DEDENT
 
 
 def test_carriage_return():