diff --git a/lisainstrument/containers.py b/lisainstrument/containers.py
index f16c584ceb280a7e3b3e282d8749b53257981ea4..3659c7fa156c0ca5a2dd2bf4cdbf5d44db5773ac 100644
--- a/lisainstrument/containers.py
+++ b/lisainstrument/containers.py
@@ -166,14 +166,14 @@ class ForEachSC(ForEachObject):
         """Return index of left MOSA."""
         if sc not in ForEachSC.indices():
             raise ValueError(f"invalid spacecraft index '{sc}'")
-        return f'{sc}{ForEachSC.distant_left(sc)}'
+        return f'{sc}{ForEachSC.distant_right(sc)}'
 
     @staticmethod
     def right_mosa(sc):
         """Return index of right MOSA."""
         if sc not in ForEachSC.indices():
             raise ValueError(f"invalid spacecraft index '{sc}'")
-        return f'{sc}{ForEachSC.distant_right(sc)}'
+        return f'{sc}{ForEachSC.distant_left(sc)}'
 
 
 class ForEachMOSA(ForEachObject):