diff --git a/conftest.py b/conftest.py
index bf66a26..55c8a38 100644
--- a/conftest.py
+++ b/conftest.py
@@ -111,6 +111,7 @@ class Checker():
     def __init__(self, version, is_passing):
         self.version = version
         self._is_passing = is_passing
+        self.grammar = parso.load_grammar(version=self.version)
 
     def parse(self, code):
         if self._is_passing:
@@ -125,7 +126,7 @@ class Checker():
             print(module.children)
 
     def get_error(self, code):
-        errors = list(parso.parse(code, version=self.version)._iter_errors())
+        errors = list(self.grammar.parse(code)._iter_errors(self.grammar))
         assert bool(errors) != self._is_passing
         if errors:
             return errors[0]
@@ -138,7 +139,7 @@ class Checker():
 
     def assert_no_error_in_passing(self, code):
         if self._is_passing:
-            assert not list(parso.parse(code, version=self.version)._iter_errors())
+            assert not list(self.grammar.parse(code)._iter_errors(self.grammar))
 
 
 @pytest.fixture
diff --git a/parso/python/normalizer.py b/parso/python/normalizer.py
index 60715a6..3694b63 100644
--- a/parso/python/normalizer.py
+++ b/parso/python/normalizer.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 from contextlib import contextmanager
 
 from parso.normalizer import Normalizer, NormalizerConfig, Issue
@@ -656,3 +657,6 @@ class ErrorFinder(Normalizer):
 
 class ErrorFinderConfig(NormalizerConfig):
     normalizer_class = ErrorFinder
+
+    def __init__(self, grammar):
+        self.grammar = grammar
diff --git a/parso/python/tree.py b/parso/python/tree.py
index d199be7..4540385 100644
--- a/parso/python/tree.py
+++ b/parso/python/tree.py
@@ -99,8 +99,8 @@ class PythonMixin(object):
                     return result
         return None
 
-    def _iter_errors(self):
-        config = normalizer.ErrorFinderConfig()
+    def _iter_errors(self, grammar):
+        config = normalizer.ErrorFinderConfig(grammar)
         return self._get_normalizer_issues(config)
 
 
diff --git a/test/normalizer_issue_files/allowed_syntax.py b/test/normalizer_issue_files/allowed_syntax.py
index 14681e5..2a7346e 100644
--- a/test/normalizer_issue_files/allowed_syntax.py
+++ b/test/normalizer_issue_files/allowed_syntax.py
@@ -39,38 +39,3 @@ except:
     pass
 except ZeroDivisionError:
     pass
-
-
-def c():
-    a = 3
-
-    def d():
-        class X():
-            nonlocal a
-
-
-def x():
-    a = 3
-
-    def y():
-        nonlocal a
-
-
-def x():
-    def y():
-        nonlocal a
-
-    a = 3
-
-
-def x():
-    a = 3
-
-    def y():
-        class z():
-            nonlocal a
-
-
-a = *args, *args
-error[(*args, *args)] = 3
-*args, *args
diff --git a/test/normalizer_issue_files/allowed_syntax_python3.6.py b/test/normalizer_issue_files/allowed_syntax_python3.6.py
index a21a608..1bbe071 100644
--- a/test/normalizer_issue_files/allowed_syntax_python3.6.py
+++ b/test/normalizer_issue_files/allowed_syntax_python3.6.py
@@ -8,3 +8,38 @@ foo[3]: int
 def glob():
     global x
     y: foo = x
+
+
+def c():
+    a = 3
+
+    def d():
+        class X():
+            nonlocal a
+
+
+def x():
+    a = 3
+
+    def y():
+        nonlocal a
+
+
+def x():
+    def y():
+        nonlocal a
+
+    a = 3
+
+
+def x():
+    a = 3
+
+    def y():
+        class z():
+            nonlocal a
+
+
+a = *args, *args
+error[(*args, *args)] = 3
+*args, *args
diff --git a/test/test_python_errors.py b/test/test_python_errors.py
index 440dcc7..923d2dd 100644
--- a/test/test_python_errors.py
+++ b/test/test_python_errors.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 """
 Testing if parso finds syntax errors and indentation errors.
 """
@@ -218,8 +219,9 @@ if sys.version_info >= (3, 4):
 
 
 def _get_error_list(code, version=None):
-    tree = parso.parse(code, version=version)
-    config = ErrorFinderConfig()
+    grammar = parso.load_grammar(version=version)
+    tree = grammar.parse(code)
+    config = ErrorFinderConfig(grammar=grammar)
     return list(tree._get_normalizer_issues(config))