diff --git a/src/hipscat_import/soap/map_reduce.py b/src/hipscat_import/soap/map_reduce.py
index 37c848d2..9f36e809 100644
--- a/src/hipscat_import/soap/map_reduce.py
+++ b/src/hipscat_import/soap/map_reduce.py
@@ -108,7 +108,10 @@ def count_joins(soap_args: SoapArguments, source_pixel: HealpixPixel, object_pix
         else:
             read_columns = [soap_args.source_object_id_column]
         source_data = file_io.read_parquet_file_to_pandas(
-            source_path, columns=read_columns, storage_options=soap_args.source_storage_options
+            source_path,
+            columns=read_columns,
+            schema=soap_args.source_catalog.schema,
+            storage_options=soap_args.source_storage_options,
         ).set_index(soap_args.source_object_id_column)
 
         remaining_sources = len(source_data)