diff --git a/git/index/base.py b/git/index/base.py
index 3bd8634c7..160d21bf3 100644
--- a/git/index/base.py
+++ b/git/index/base.py
@@ -873,7 +873,7 @@ def move(self, items, skip_errors=False, **kwargs):
 
         return out
 
-    def commit(self, message, parent_commits=None, head=True):
+    def commit(self, message, parent_commits=None, head=True, author=None, committer=None):
         """Commit the current default index file, creating a commit object.
 
         For more information on the arguments, see tree.commit.
@@ -884,7 +884,7 @@ def commit(self, message, parent_commits=None, head=True):
         :return:
             Commit object representing the new commit"""
         tree = self.write_tree()
-        return Commit.create_from_tree(self.repo, tree, message, parent_commits, head)
+        return Commit.create_from_tree(self.repo, tree, message, parent_commits, head, author=author, committer=committer)
 
     @classmethod
     def _flush_stdin_and_wait(cls, proc, ignore_stdout = False):
diff --git a/git/objects/commit.py b/git/objects/commit.py
index cbfd5097b..f1c2a23d1 100644
--- a/git/objects/commit.py
+++ b/git/objects/commit.py
@@ -254,7 +254,7 @@ def _iter_from_process_or_stream(cls, repo, proc_or_stream):
         
         
     @classmethod
-    def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False):
+    def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False, author=None, committer=None):
         """Commit the given tree, creating a commit object.
         
         :param repo: Repo object the commit should be part of 
@@ -299,8 +299,13 @@ def create_from_tree(cls, repo, tree, message, parent_commits=None, head=False):
         cr = repo.config_reader()
         env = os.environ
         
-        committer = Actor.committer(cr)
-        author = Actor.author(cr)
+        if author is None and committer is None:
+            committer = Actor.committer(cr)
+            author = Actor.author(cr)
+        elif author is None:
+            author = Actor.author(cr)
+        elif committer is None:
+            committer = Actor.committer(cr)
         
         # PARSE THE DATES
         unix_time = int(time())
diff --git a/git/refs/log.py b/git/refs/log.py
index 9a719ec06..560ffd3e1 100644
--- a/git/refs/log.py
+++ b/git/refs/log.py
@@ -247,7 +247,7 @@ def append_entry(cls, config_reader, filepath, oldbinsha, newbinsha, message):
             raise ValueError("Shas need to be given in binary format")
         #END handle sha type
         assure_directory_exists(filepath, is_file=True)
-        entry = RefLogEntry((bin_to_hex(oldbinsha), bin_to_hex(newbinsha), Actor.committer(config_reader), (int(time.time()), time.altzone), message))
+        entry = RefLogEntry((bin_to_hex(oldbinsha), bin_to_hex(newbinsha), config_reader, (int(time.time()), time.altzone), message))
         
         lf = LockFile(filepath)
         lf._obtain_lock_or_raise()
diff --git a/git/refs/symbolic.py b/git/refs/symbolic.py
index ef21950fa..5374285e0 100644
--- a/git/refs/symbolic.py
+++ b/git/refs/symbolic.py
@@ -355,7 +355,7 @@ def log_append(self, oldbinsha, message, newbinsha=None):
         :param newbinsha: The sha the ref points to now. If None, our current commit sha
             will be used
         :return: added RefLogEntry instance"""
-        return RefLog.append_entry(self.repo.config_reader(), RefLog.path(self), oldbinsha, 
+        return RefLog.append_entry(self.commit.committer, RefLog.path(self), oldbinsha, 
                                     (newbinsha is None and self.commit.binsha) or newbinsha, 
                                     message)