diff --git a/migrations/009_item_extended_fields.sql b/migrations/010_item_extended_fields.sql
similarity index 100%
rename from migrations/009_item_extended_fields.sql
rename to migrations/010_item_extended_fields.sql
diff --git a/pkg/freecad/silo_commands.py b/pkg/freecad/silo_commands.py
index 9e7c698..0e465dd 100644
--- a/pkg/freecad/silo_commands.py
+++ b/pkg/freecad/silo_commands.py
@@ -534,6 +534,17 @@ class SiloClient:
         except Exception:
             return False, None
 
+    def latest_file_revision(self, part_number: str) -> Optional[Dict]:
+        """Return the most recent revision that has a file attached, or None."""
+        try:
+            revisions = self.get_revisions(part_number)
+            for rev in revisions:  # revisions come newest-first from the API
+                if rev.get("file_key"):
+                    return rev
+            return None
+        except Exception:
+            return None
+
     def compare_revisions(
         self, part_number: str, from_rev: int, to_rev: int
     ) -> Dict[str, Any]:
@@ -1757,9 +1768,11 @@ class Silo_Push:
         }
 
     def Activated(self):
+        from datetime import datetime, timezone
+
         from PySide import QtGui
 
-        # Find unuploaded files
+        # Find files that need uploading (no server file, or local is newer)
         local_files = search_local_files()
         unuploaded = []
 
@@ -1767,9 +1780,30 @@ class Silo_Push:
             pn = lf["part_number"]
             try:
                 _client.get_item(pn)  # Check if in DB
-                has_file, _ = _client.has_file(pn)
-                if not has_file:
+                server_rev = _client.latest_file_revision(pn)
+                if not server_rev:
+                    # No file on server at all
                     unuploaded.append(lf)
+                else:
+                    # Compare local mtime against server revision timestamp
+                    try:
+                        local_mtime = os.path.getmtime(lf["path"])
+                        server_time_str = server_rev.get("created_at", "")
+                        if server_time_str:
+                            server_dt = datetime.fromisoformat(
+                                server_time_str.replace("Z", "+00:00")
+                            )
+                            local_dt = datetime.fromtimestamp(
+                                local_mtime, tz=timezone.utc
+                            )
+                            if local_dt > server_dt:
+                                unuploaded.append(lf)
+                        else:
+                            # Can't parse server time, assume needs upload
+                            unuploaded.append(lf)
+                    except Exception:
+                        # On any comparison error, include it
+                        unuploaded.append(lf)
             except Exception:
                 pass  # Not in DB, skip