diff --git a/lib/tfw/yaml_fsm.py b/lib/tfw/yaml_fsm.py
index 9b5f331..fe854ba 100644
--- a/lib/tfw/yaml_fsm.py
+++ b/lib/tfw/yaml_fsm.py
@@ -10,7 +10,7 @@ from tfw import FSMBase
 class YamlFSM(FSMBase):
     def __init__(self, config_file):
         self.config = self.parse_config(config_file)
-        self.patch_config_callbacks()
+        self.for_config_states_and_transitions_do(self.patch_config_callbacks)
         self.setup_states()
         super().__init__()  # FSMBase.__init__() requires states
         self.setup_transitions()
@@ -27,14 +27,16 @@ class YamlFSM(FSMBase):
         for transition in self.config['transitions']:
             self.add_transition(**transition)
 
-    def patch_config_callbacks(self):
-        topatch = ('on_enter', 'on_exit', 'prepare', 'before', 'after')
-
+    def for_config_states_and_transitions_do(self, what):
         for array in ('states', 'transitions'):
             for json_obj in self.config[array]:
-                for key in json_obj:
-                    if key in topatch:
-                        json_obj[key] = partial(self.run, json_obj[key])
+                what(json_obj)
+
+    def patch_config_callbacks(self, json_obj):
+        topatch = ('on_enter', 'on_exit', 'prepare', 'before', 'after')
+        for key in json_obj:
+            if key in topatch:
+                json_obj[key] = partial(self.run, json_obj[key])
 
     @staticmethod
     def run(command, event):