diff --git a/fs_uae_wrapper/base.py b/fs_uae_wrapper/base.py
index 74d7b0d..919ecb7 100644
--- a/fs_uae_wrapper/base.py
+++ b/fs_uae_wrapper/base.py
@@ -195,7 +195,6 @@ class Base(object):
         for num in range(10):
             include_list.append('hard_drive_%d' % num)
 
-        conf_abs_dir = os.path.dirname(os.path.abspath(self.conf_file))
         changed_options = {}
 
         for key, val in utils.get_config(self.conf_file).items():
@@ -212,7 +211,7 @@ class Base(object):
                 continue
 
             if val.startswith('$CONFIG'):
-                abspath = os.path.abspath(val.replace('$CONFIG', conf_abs_dir))
+                abspath = utils.interpolate_variables(val, self.conf_file)
                 changed_options[key] = abspath
                 continue
 
diff --git a/fs_uae_wrapper/utils.py b/fs_uae_wrapper/utils.py
index 812804a..583687f 100644
--- a/fs_uae_wrapper/utils.py
+++ b/fs_uae_wrapper/utils.py
@@ -145,8 +145,9 @@ def interpolate_variables(string, config_path, base=None):
     """
 
     if '$CONFIG' in string:
-        string = string.replace('$CONFIG',
-                                os.path.dirname(os.path.abspath(config_path)))
+        conf_path = os.path.dirname(os.path.abspath(config_path))
+        string = os.path.abspath(string.replace('$CONFIG', conf_path))
+
     if '$HOME' in string:
         string = string.replace('$HOME', os.path.expandvars('$HOME'))
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 054760c..76b8f62 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -241,26 +241,26 @@ class TestCmdOptions(TestCase):
 
         itrpl = utils.interpolate_variables
 
-        string = 'foo = $CONFIG/../path/to/smth'
+        string = '$CONFIG/../path/to/smth'
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae'),
-                         'foo = /home/user/../path/to/smth')
-        string = 'bar = $HOME'
+                         '/home/path/to/smth')
+        string = '$HOME'
         expandv.return_value = '/home/user'
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae'),
-                         'bar = /home/user')
+                         '/home/user')
 
-        string = 'foo = $APP/$EXE'
+        string = '$APP/$EXE'
         find_exe.return_value = '/usr/bin/fs-uae'
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae'),
-                         'foo = /usr/bin/fs-uae//usr/bin/fs-uae')
+                         '/usr/bin/fs-uae//usr/bin/fs-uae')
 
-        string = 'docs = $DOCUMENTS'
+        string = '$DOCUMENTS'
         getenv.return_value = '/home/user/Docs'
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae'),
-                         'docs = /home/user/Docs')
+                         '/home/user/Docs')
 
-        string = 'baz = $BASE'
+        string = '$BASE'
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae'),
-                         'baz = $BASE')
+                         '$BASE')
         self.assertEqual(itrpl(string, '/home/user/Config.fs-uae', 'base'),
-                         'baz = base')
+                         'base')