diff --git a/model_utils/tracker.py b/model_utils/tracker.py
index b80d3b9..e38d81f 100644
--- a/model_utils/tracker.py
+++ b/model_utils/tracker.py
@@ -9,7 +9,7 @@ class FieldInstanceTracker(object):
         self.fields = fields
         self.field_map = field_map
 
-    def get_field(self, field):
+    def get_field_value(self, field):
         return getattr(self.instance, self.field_map[field])
 
     def set_saved_fields(self, fields=None):
@@ -23,7 +23,7 @@ class FieldInstanceTracker(object):
     def current(self, fields=None):
         if fields is None:
             fields = self.fields
-        return dict((f, self.get_field(f)) for f in fields)
+        return dict((f, self.get_field_value(f)) for f in fields)
 
     def has_changed(self, field):
         """Returns ``True`` if field has changed from currently saved value"""
@@ -54,11 +54,13 @@ class FieldTracker(object):
     def __init__(self, fields=None):
         self.fields = fields
 
-    def set_field_map(self, cls):
-        self.field_map = dict((field, field) for field in self.fields)
+    def get_field_map(self, cls):
+        """Return ``dict`` mapping fields to model instance attribute names"""
+        field_map = dict((field, field) for field in self.fields)
         all_fields = dict((f.name, f.attname) for f in cls._meta.local_fields)
-        self.field_map.update(**dict((k, v) for (k, v) in all_fields.items()
-                                     if k in self.field_map))
+        field_map.update(**dict((k, v) for (k, v) in all_fields.items()
+                                if k in field_map))
+        return field_map
 
     def contribute_to_class(self, cls, name):
         self.name = name
@@ -68,7 +70,7 @@ class FieldTracker(object):
     def finalize_class(self, sender, **kwargs):
         if self.fields is None:
             self.fields = [field.attname for field in sender._meta.local_fields]
-        self.set_field_map(sender)
+        self.field_map = self.get_field_map(sender)
         models.signals.post_init.connect(self.initialize_tracker, sender=sender)
         setattr(sender, self.name, self)
 
@@ -101,5 +103,5 @@ class ModelInstanceTracker(FieldInstanceTracker):
 class ModelTracker(FieldTracker):
     tracker_class = ModelInstanceTracker
 
-    def set_field_map(self, cls):
-        self.field_map = dict((field, field) for field in self.fields)
+    def get_field_map(self, cls):
+        return dict((field, field) for field in self.fields)