diff --git a/docs/cli-reference.rst b/docs/cli-reference.rst
index 9a025ba..c194967 100644
--- a/docs/cli-reference.rst
+++ b/docs/cli-reference.rst
@@ -349,6 +349,7 @@ See :ref:`cli_bulk`.
 
     Options:
       --batch-size INTEGER   Commit every X records
+      --functions TEXT       Python code defining one or more custom SQL functions
       --flatten              Flatten nested JSON objects, so {"a": {"b": 1}} becomes
                              {"a_b": 1}
       --nl                   Expect newline-delimited JSON
diff --git a/sqlite_utils/cli.py b/sqlite_utils/cli.py
index 24c8c03..16a99cc 100644
--- a/sqlite_utils/cli.py
+++ b/sqlite_utils/cli.py
@@ -926,9 +926,12 @@ def insert_upsert_implementation(
     load_extension=None,
     silent=False,
     bulk_sql=None,
+    functions=None,
 ):
     db = sqlite_utils.Database(path)
     _load_extensions(db, load_extension)
+    if functions:
+        _register_functions(db, functions)
     if (delimiter or quotechar or sniff or no_headers) and not tsv:
         csv = True
     if (nl + csv + tsv) >= 2:
@@ -1305,6 +1308,9 @@ def upsert(
 @click.argument("sql")
 @click.argument("file", type=click.File("rb"), required=True)
 @click.option("--batch-size", type=int, default=100, help="Commit every X records")
+@click.option(
+    "--functions", help="Python code defining one or more custom SQL functions"
+)
 @import_options
 @load_extension_option
 def bulk(
@@ -1312,6 +1318,7 @@ def bulk(
     sql,
     file,
     batch_size,
+    functions,
     flatten,
     nl,
     csv,
@@ -1368,6 +1375,7 @@ def bulk(
             load_extension=load_extension,
             silent=False,
             bulk_sql=sql,
+            functions=functions,
         )
     except (OperationalError, sqlite3.IntegrityError) as e:
         raise click.ClickException(str(e))
diff --git a/tests/test_cli_bulk.py b/tests/test_cli_bulk.py
index 6d01952..909ed09 100644
--- a/tests/test_cli_bulk.py
+++ b/tests/test_cli_bulk.py
@@ -28,9 +28,11 @@ def test_cli_bulk(test_db_and_path):
         [
             "bulk",
             db_path,
-            "insert into example (id, name) values (:id, :name)",
+            "insert into example (id, name) values (:id, myupper(:name))",
             "-",
             "--nl",
+            "--functions",
+            "myupper = lambda s: s.upper()",
         ],
         input='{"id": 3, "name": "Three"}\n{"id": 4, "name": "Four"}\n',
     )
@@ -38,8 +40,8 @@ def test_cli_bulk(test_db_and_path):
     assert [
         {"id": 1, "name": "One"},
         {"id": 2, "name": "Two"},
-        {"id": 3, "name": "Three"},
-        {"id": 4, "name": "Four"},
+        {"id": 3, "name": "THREE"},
+        {"id": 4, "name": "FOUR"},
     ] == list(db["example"].rows)