diff --git a/src/pypi_data/cli.py b/src/pypi_data/cli.py
index a09c9a9a..95bf0c22 100644
--- a/src/pypi_data/cli.py
+++ b/src/pypi_data/cli.py
@@ -123,7 +123,7 @@ def print_thread():
                        f"PRAGMA memory_limit='2GB'; "
                        f"PRAGMA enable_profiling;"
                        f"{sql}",
-                       parameters=[parameter] if parameter else [])
+                       parameters=[[parameter]] if parameter else [])
     try:
         for name, plan in duckdb.fetchall():
             print(name)