diff --git a/py/hexagram/gauge.py b/py/hexagram/gauge.py
index 6401a27..21bf396 100644
--- a/py/hexagram/gauge.py
+++ b/py/hexagram/gauge.py
@@ -6,8 +6,12 @@ class Gauge():
     def __init__(self):
         self.value = None
 
+    def set_value(self, value):
+        self.value = value
+
     def draw_bg(self, cr: cairo.Context):
         raise NotImplementedError
 
-    def set_value(self, value):
-        self.value = value
+    def draw_fg(self, cr: cairo.Context):
+        raise NotImplementedError
+