diff --git a/api/s23_options.py b/api/s23_options.py
index 43e6ada..b0580ed 100644
--- a/api/s23_options.py
+++ b/api/s23_options.py
@@ -142,6 +142,12 @@ def set_option(name: str, cs: ChangeSet) -> ChangeSet:
 # HYDRAULICS          USE/SAVE  filename
 # MAP                 filename
 #--------------------------------------------------------------
+
+
+def _sync_to_v3() -> ChangeSet:
+    return ChangeSet()
+
+
 def inp_in_option(section: list[str]) -> ChangeSet:
     if len(section) <= 0:
         return ChangeSet()
@@ -165,7 +171,10 @@ def inp_in_option(section: list[str]) -> ChangeSet:
                 if line.startswith(key):
                     value = line.removeprefix(key).strip()
                     cs |= { key : value }
-    return ChangeSet(cs)
+
+    result = ChangeSet(cs)
+    result.merge(_sync_to_v3())
+    return result
 
 
 def inp_out_option(name: str) -> list[str]: