diff --git a/spacy/cli/init_config.py b/spacy/cli/init_config.py
index 9880c389c..55622452b 100644
--- a/spacy/cli/init_config.py
+++ b/spacy/cli/init_config.py
@@ -10,7 +10,8 @@ from jinja2 import Template
 from .. import util
 from ..language import DEFAULT_CONFIG_PRETRAIN_PATH
 from ..schemas import RecommendationSchema
-from ._util import init_cli, Arg, Opt, show_validation_error, COMMAND, string_to_list
+from ._util import init_cli, Arg, Opt, show_validation_error, COMMAND
+from ._util import string_to_list, import_code
 
 
 ROOT = Path(__file__).parent / "templates"
@@ -70,7 +71,8 @@ def init_fill_config_cli(
     base_path: Path = Arg(..., help="Base config to fill", exists=True, dir_okay=False),
     output_file: Path = Arg("-", help="File to save config.cfg to (or - for stdout)", allow_dash=True),
     pretraining: bool = Opt(False, "--pretraining", "-pt", help="Include config for pretraining (with 'spacy pretrain')"),
-    diff: bool = Opt(False, "--diff", "-D", help="Print a visual diff highlighting the changes")
+    diff: bool = Opt(False, "--diff", "-D", help="Print a visual diff highlighting the changes"),
+    code_path: Optional[Path] = Opt(None, "--code-path", "--code", "-c", help="Path to Python file with additional code (registered functions) to be imported"),
     # fmt: on
 ):
     """
@@ -82,6 +84,7 @@ def init_fill_config_cli(
 
     DOCS: https://spacy.io/api/cli#init-fill-config
     """
+    import_code(code_path)
     fill_config(output_file, base_path, pretraining=pretraining, diff=diff)
 
 
diff --git a/website/docs/api/cli.md b/website/docs/api/cli.md
index e8be0f79c..8564eff43 100644
--- a/website/docs/api/cli.md
+++ b/website/docs/api/cli.md
@@ -170,14 +170,15 @@ validation error with more details.
 $ python -m spacy init fill-config [base_path] [output_file] [--diff]
 ```
 
-| Name                   | Description                                                                                                                         |
-| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------- |
-| `base_path`            | Path to base config to fill, e.g. generated by the [quickstart widget](/usage/training#quickstart). ~~Path (positional)~~           |
-| `output_file`          | Path to output `.cfg` file. If not set, the config is written to stdout so you can pipe it forward to a file. ~~Path (positional)~~ |
-| `--pretraining`, `-pt` | Include config for pretraining (with [`spacy pretrain`](/api/cli#pretrain)). Defaults to `False`. ~~bool (flag)~~                   |
-| `--diff`, `-D`         | Print a visual diff highlighting the changes. ~~bool (flag)~~                                                                       |
-| `--help`, `-h`         | Show help message and available arguments. ~~bool (flag)~~                                                                          |
-| **CREATES**            | Complete and auto-filled config file for training.                                                                                  |
+| Name                   | Description                                                                                                                                                                          |
+| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| `base_path`            | Path to base config to fill, e.g. generated by the [quickstart widget](/usage/training#quickstart). ~~Path (positional)~~                                                            |
+| `output_file`          | Path to output `.cfg` file. If not set, the config is written to stdout so you can pipe it forward to a file. ~~Path (positional)~~                                                  |
+| `--code`, `-c`         | Path to Python file with additional code to be imported. Allows [registering custom functions](/usage/training#custom-functions) for new architectures. ~~Optional[Path] \(option)~~ |
+| `--pretraining`, `-pt` | Include config for pretraining (with [`spacy pretrain`](/api/cli#pretrain)). Defaults to `False`. ~~bool (flag)~~                                                                    |
+| `--diff`, `-D`         | Print a visual diff highlighting the changes. ~~bool (flag)~~                                                                                                                        |
+| `--help`, `-h`         | Show help message and available arguments. ~~bool (flag)~~                                                                                                                           |
+| **CREATES**            | Complete and auto-filled config file for training.                                                                                                                                   |
 
 ### init vectors {#init-vectors new="3" tag="command"}