diff --git a/docs/output.md b/docs/output.md
index ddbbe70..ac01eda 100644
--- a/docs/output.md
+++ b/docs/output.md
@@ -209,7 +209,7 @@ parquet file page size. default: 8192 bytes
 
 ### parquet_row_group_size
 
-parquet file row group size. default: 128 MB
+parquet file row group size. default: 128 MiB
 
 ### record_type