diff --git a/lib/iris/cube.py b/lib/iris/cube.py
index d8f9992af0..daffe11835 100644
--- a/lib/iris/cube.py
+++ b/lib/iris/cube.py
@@ -2182,6 +2182,7 @@ def _summary_coord_extra(self, coord, indent):
         extra = ""
         similar_coords = self.coords(coord.name())
         if len(similar_coords) > 1:
+            similar_coords.remove(coord)
             # Look for any attributes that vary.
             vary = set()
             for key, value in coord.attributes.items():