diff --git a/include/pygit2/config.h b/include/pygit2/config.h
index b07849e..62dbc83 100644
--- a/include/pygit2/config.h
+++ b/include/pygit2/config.h
@@ -34,7 +34,7 @@
 
 PyObject* Config_get_global_config(void);
 PyObject* Config_get_system_config(void);
-PyObject* Config_add_file(Config *self, PyObject *args);
+PyObject* Config_add_file(Config *self, PyObject *args, PyObject *kwds);
 PyObject* Config_getitem(Config *self, PyObject *key);
 PyObject* Config_foreach(Config *self, PyObject *args);
 PyObject* Config_get_multivar(Config *self, PyObject *args);
diff --git a/setup.py b/setup.py
index 7a8dce8..59f5bc3 100644
--- a/setup.py
+++ b/setup.py
@@ -30,6 +30,7 @@
 
 from __future__ import print_function
 
+import codecs
 import os
 from subprocess import Popen, PIPE
 import sys
@@ -162,7 +163,7 @@ classifiers = [
     "Topic :: Software Development :: Version Control"]
 
 
-with open('README.rst') as readme:
+with codecs.open('README.rst', 'r', 'utf-8') as readme:
     long_description = readme.read()
 
 setup(name='pygit2',
diff --git a/src/pygit2/config.c b/src/pygit2/config.c
index d850ba8..0983bac 100644
--- a/src/pygit2/config.c
+++ b/src/pygit2/config.c
@@ -214,8 +214,7 @@ Config_setitem(Config *self, PyObject *py_key, PyObject *py_value)
 }
 
 int
-Config_foreach_callback_wrapper(const char *c_name, const char *c_value,
-        void *c_payload)
+Config_foreach_callback_wrapper(const git_config_entry *entry, void *c_payload)
 {
     PyObject *args = (PyObject *)c_payload;
     PyObject *py_callback = NULL;
@@ -224,18 +223,20 @@ Config_foreach_callback_wrapper(const char *c_name, const char *c_value,
     int c_result;
 
     if (!PyArg_ParseTuple(args, "O|O", &py_callback, &py_payload))
-        return 0;
+        return -1;
 
     if (py_payload)
-        args = Py_BuildValue("ssO", c_name, c_value, py_payload);
+        args = Py_BuildValue("ssO", entry->name, entry->value, py_payload);
     else
-        args = Py_BuildValue("ss", c_name, c_value);
+        args = Py_BuildValue("ss", entry->name, entry->value);
+    if (!args)
+        return -1;
 
     if (!(py_result = PyObject_CallObject(py_callback,args)))
-        return 0;
+        return -1;
 
-    if (!(c_result = PyLong_AsLong(py_result)))
-        return 0;
+    if ((c_result = PyLong_AsLong(py_result) == -1))
+        return -1;
 
     return c_result;
 }
@@ -264,16 +265,20 @@ Config_foreach(Config *self, PyObject *args)
 }
 
 PyObject *
-Config_add_file(Config *self, PyObject *args)
+Config_add_file(Config *self, PyObject *args, PyObject *kwds)
 {
+    char *keywords[] = {"path", "level", "force", NULL};
     int err;
     char *path;
-    int priority;
+    unsigned int level = 0;
+    int force = 0;
 
-    if (!PyArg_ParseTuple(args, "si", &path, &priority))
+    if (!PyArg_ParseTupleAndKeywords(
+            args, kwds, "s|Ii", keywords,
+            &path, &level, &force))
         return NULL;
 
-    err = git_config_add_file_ondisk(self->config, path, priority);
+    err = git_config_add_file_ondisk(self->config, path, level, force);
     if (err < 0) {
         Error_set_str(err, path);
         return NULL;
@@ -283,12 +288,12 @@ Config_add_file(Config *self, PyObject *args)
 }
 
 int
-Config_get_multivar_fn_wrapper(const char *value, void *data)
+Config_get_multivar_fn_wrapper(const git_config_entry *value, void *data)
 {
     PyObject *list = (PyObject *)data;
     PyObject *item = NULL;
 
-    if (!(item = PyUnicode_FromString(value)))
+    if (!(item = PyUnicode_FromString(value->value)))
         return -2;
 
     PyList_Append(list, item);
@@ -353,7 +358,7 @@ PyMethodDef Config_methods[] = {
      "and value of each variable in the config backend, and an optional "
      "payload passed to this method. As soon as one of the callbacks returns "
      "an integer other than 0, this function returns that value."},
-    {"add_file", (PyCFunction)Config_add_file, METH_VARARGS,
+    {"add_file", (PyCFunction)Config_add_file, METH_VARARGS | METH_KEYWORDS,
      "Add a config file instance to an existing config."},
     {"get_multivar", (PyCFunction)Config_get_multivar, METH_VARARGS,
      "Get each value of a multivar ''name'' as a list. The optional ''regex'' "
diff --git a/src/pygit2/diff.c b/src/pygit2/diff.c
index 4fc44eb..d010442 100644
--- a/src/pygit2/diff.c
+++ b/src/pygit2/diff.c
@@ -42,8 +42,8 @@ extern PyTypeObject HunkType;
 
 static int diff_data_cb(
   void *cb_data,
-  git_diff_delta *delta,
-  git_diff_range *range,
+  const git_diff_delta *delta,
+  const git_diff_range *range,
   char line_origin,
   const char *content,
   size_t content_len)
@@ -75,8 +75,8 @@ static int diff_data_cb(
 
 static int diff_hunk_cb(
   void *cb_data,
-  git_diff_delta *delta,
-  git_diff_range *range,
+  const git_diff_delta *delta,
+  const git_diff_range *range,
   const char *header,
   size_t header_len)
 {
@@ -158,7 +158,8 @@ static int diff_hunk_cb(
     return 0;
 };
 
-static int diff_file_cb(void *cb_data, git_diff_delta *delta, float progress)
+static int diff_file_cb(void *cb_data, const git_diff_delta *delta,
+  float progress)
 {
     PyObject *files, *file;
 
@@ -201,8 +202,8 @@ Diff_changes(Diff *self)
 
 static int diff_print_cb(
     void *cb_data,
-    git_diff_delta *delta,
-    git_diff_range *range,
+    const git_diff_delta *delta,
+    const git_diff_range *range,
     char usage,
     const char *line,
     size_t line_len)
diff --git a/src/pygit2/index.c b/src/pygit2/index.c
index d0de48e..8681bd3 100644
--- a/src/pygit2/index.c
+++ b/src/pygit2/index.c
@@ -84,12 +84,11 @@ Index_add(Index *self, PyObject *args)
 {
     int err;
     const char *path;
-    int stage=0;
 
-    if (!PyArg_ParseTuple(args, "s|i", &path, &stage))
+    if (!PyArg_ParseTuple(args, "s", &path))
         return NULL;
 
-    err = git_index_add(self->index, path, stage);
+    err = git_index_add_from_workdir(self->index, path);
     if (err < 0)
         return Error_set_str(err, path);
 
@@ -281,7 +280,7 @@ Index_getitem(Index *self, PyObject *value)
     if (idx == -1)
         return NULL;
 
-    index_entry = git_index_get(self->index, idx);
+    index_entry = git_index_get_byindex(self->index, idx);
     if (!index_entry) {
         PyErr_SetObject(PyExc_KeyError, value);
         return NULL;
@@ -290,27 +289,35 @@ Index_getitem(Index *self, PyObject *value)
     return wrap_index_entry(index_entry, self);
 }
 
+PyObject *
+Index_remove(Index *self, PyObject *args)
+{
+    int err;
+    const char *path;
+
+    if (!PyArg_ParseTuple(args, "s", &path))
+        return NULL;
+
+    err = git_index_remove(self->index, path, 0);
+    if (err < 0) {
+        Error_set(err);
+        return NULL;
+    }
+
+    Py_RETURN_NONE;
+}
+
 int
 Index_setitem(Index *self, PyObject *key, PyObject *value)
 {
-    int err;
-    int idx;
-
-    if (value) {
+    if (value != NULL) {
         PyErr_SetString(PyExc_NotImplementedError,
                         "set item on index not yet implemented");
         return -1;
     }
 
-    idx = Index_get_position(self, key);
-    if (idx == -1)
-        return -1;
-
-    err = git_index_remove(self->index, idx);
-    if (err < 0) {
-        Error_set(err);
-        return -1;
-    }
+    if(Index_remove(self, Py_BuildValue("(N)", key)) == NULL)
+      return -1;
 
     return 0;
 }
@@ -331,7 +338,7 @@ Index_read_tree(Index *self, PyObject *value)
     if (err < 0)
         return Error_set(err);
 
-    err = git_index_read_tree(self->index, tree, NULL);
+    err = git_index_read_tree(self->index, tree);
     if (err < 0)
         return Error_set(err);
 
@@ -344,7 +351,7 @@ Index_write_tree(Index *self)
     git_oid oid;
     int err;
 
-    err = git_tree_create_fromindex(&oid, self->index);
+    err = git_index_write_tree(&oid, self->index);
     if (err < 0)
         return Error_set(err);
 
@@ -354,6 +361,8 @@ Index_write_tree(Index *self)
 PyMethodDef Index_methods[] = {
     {"add", (PyCFunction)Index_add, METH_VARARGS,
      "Add or update an index entry from a file in disk."},
+    {"remove", (PyCFunction)Index_remove, METH_VARARGS,
+     "Removes an entry from index."},
     {"clear", (PyCFunction)Index_clear, METH_NOARGS,
      "Clear the contents (all the entries) of an index object."},
     {"diff", (PyCFunction)Index_diff_tree, METH_VARARGS,
@@ -447,7 +456,7 @@ IndexIter_iternext(IndexIter *self)
 {
     git_index_entry *index_entry;
 
-    index_entry = git_index_get(self->owner->index, self->i);
+    index_entry = git_index_get_byindex(self->owner->index, self->i);
     if (!index_entry)
         return NULL;
 
diff --git a/test/test_config.py b/test/test_config.py
index c2bd9f2..8656436 100644
--- a/test/test_config.py
+++ b/test/test_config.py
@@ -39,6 +39,7 @@ config_filename = "test_config"
 def foreach_test_wrapper(key, name, lst):
     lst[key] = name
     return 0
+foreach_test_wrapper.__test__ = False
 
 class ConfigTest(utils.RepoTestCase):
 
@@ -150,7 +151,7 @@ class ConfigTest(utils.RepoTestCase):
         new_file.write("[this]\n\tthat = foobar\n\tthat = foobeer\n")
         new_file.close()
 
-        config.add_file(config_filename, 0)
+        config.add_file(config_filename, 5)
         self.assertTrue('this.that' in config)
         config.set_multivar('this.that', '^.*beer', 'fool')
         l = config.get_multivar('this.that', 'fool')
diff --git a/test/test_index.py b/test/test_index.py
index da77840..8950cbc 100644
--- a/test/test_index.py
+++ b/test/test_index.py
@@ -80,7 +80,7 @@ class IndexTest(utils.RepoTestCase):
 
     def test_write(self):
         index = self.repo.index
-        index.add('bye.txt', 0)
+        index.add('bye.txt')
         index.write()
 
         index.clear()
@@ -133,7 +133,15 @@ class IndexTest(utils.RepoTestCase):
         self.assertEqual([x.hex for x in index],
                 [x.hex for x in self.repo.index])
 
-        self.assertRaises(pygit2.GitError, lambda: index.add('bye.txt', 0))
+        self.assertRaises(pygit2.GitError, lambda: index.add('bye.txt'))
+
+    def test_del(self):
+        index = self.repo.index
+        del index['hello.txt']
+
+    def test_remove(self):
+        index = self.repo.index
+        index.remove('hello.txt')
 
 if __name__ == '__main__':
     unittest.main()