diff --git a/src/cal_tools/jungfraulib.py b/src/cal_tools/jungfraulib.py
index 4171b228e78f482ec9de6a7eb6cda31e64cf0717..c8f15c2469a30fb4cd7bfbfe38094c3be8b7d239 100644
--- a/src/cal_tools/jungfraulib.py
+++ b/src/cal_tools/jungfraulib.py
@@ -217,7 +217,8 @@ def replace_pixels_wrong_gain_badpixel(
     badpixel_map,
     memory_cells,
 ):
-    """_summary_
+    """Replace the gain value with the given new gain value for pixels
+    indicated as bad with WRONG_GAIN_VALUE bit.
 
     Args:
         gain_arr (ndarray): The raw gain array to be updated.