diff --git a/src/graphnet/data/writers/sqlite_writer.py b/src/graphnet/data/writers/sqlite_writer.py
index d7cc48297..ab8d95051 100644
--- a/src/graphnet/data/writers/sqlite_writer.py
+++ b/src/graphnet/data/writers/sqlite_writer.py
@@ -181,6 +181,7 @@ def _merge_databases(
                     database_path=database_path,
                     index_column=primary_key,
                     integer_primary_key=integer_primary_key,
+                    default_type="FLOAT",
                 )
 
                 # Update row counts if needed