diff --git a/flytekit/clis/sdk_in_container/helpers.py b/flytekit/clis/sdk_in_container/helpers.py
index a9a9c4900d..72246bcba4 100644
--- a/flytekit/clis/sdk_in_container/helpers.py
+++ b/flytekit/clis/sdk_in_container/helpers.py
@@ -1,7 +1,10 @@
+from dataclasses import replace
+from typing import Optional
+
 import click
 
 from flytekit.clis.sdk_in_container.constants import CTX_CONFIG_FILE
-from flytekit.configuration import Config
+from flytekit.configuration import Config, ImageConfig
 from flytekit.loggers import cli_logger
 from flytekit.remote.remote import FlyteRemote
 
@@ -30,3 +33,28 @@ def get_and_save_remote_with_click_context(
     if save:
         ctx.obj[FLYTE_REMOTE_INSTANCE_KEY] = r
     return r
+
+
+def patch_image_config(config_file: Optional[str], image_config: ImageConfig) -> ImageConfig:
+    """
+    Merge ImageConfig object with images defined in config file
+    """
+    # Images come from three places:
+    # * The default flytekit images, which are already supplied by the base run_level_params.
+    # * The images provided by the user on the command line.
+    # * The images provided by the user via the config file, if there is one. (Images on the command line should
+    #   override all).
+    #
+    # However, the run_level_params already contains both the default flytekit images (lowest priority), as well
+    # as the images from the command line (highest priority). So when we read from the config file, we only
+    # want to add in the images that are missing, including the default, if that's also missing.
+    additional_image_names = set([v.name for v in image_config.images])
+    new_additional_images = [v for v in image_config.images]
+    new_default = image_config.default_image
+    if config_file:
+        cfg_ic = ImageConfig.auto(config_file=config_file)
+        new_default = new_default or cfg_ic.default_image
+        for addl in cfg_ic.images:
+            if addl.name not in additional_image_names:
+                new_additional_images.append(addl)
+    return replace(image_config, default_image=new_default, images=new_additional_images)
diff --git a/flytekit/clis/sdk_in_container/register.py b/flytekit/clis/sdk_in_container/register.py
index c0bdcd2416..9f4ba1a81c 100644
--- a/flytekit/clis/sdk_in_container/register.py
+++ b/flytekit/clis/sdk_in_container/register.py
@@ -6,7 +6,7 @@
 
 from flytekit.clis.helpers import display_help_with_error
 from flytekit.clis.sdk_in_container import constants
-from flytekit.clis.sdk_in_container.helpers import get_and_save_remote_with_click_context
+from flytekit.clis.sdk_in_container.helpers import get_and_save_remote_with_click_context, patch_image_config
 from flytekit.configuration import FastSerializationSettings, ImageConfig, SerializationSettings
 from flytekit.configuration.default_images import DefaultImages
 from flytekit.loggers import cli_logger
@@ -137,12 +137,20 @@ def register(
     if pkgs:
         raise ValueError("Unimplemented, just specify pkgs like folder/files as args at the end of the command")
 
+    if non_fast and not version:
+        raise ValueError("Version is a required parameter in case --non-fast is specified.")
+
     if len(package_or_module) == 0:
         display_help_with_error(
             ctx,
             "Missing argument 'PACKAGE_OR_MODULE...', at least one PACKAGE_OR_MODULE is required but multiple can be passed",
         )
 
+    # Use extra images in the config file if that file exists
+    config_file = ctx.obj.get(constants.CTX_CONFIG_FILE)
+    if config_file:
+        image_config = patch_image_config(config_file, image_config)
+
     cli_logger.debug(
         f"Running pyflyte register from {os.getcwd()} "
         f"with images {image_config} "
@@ -155,12 +163,12 @@ def register(
 
     detected_root = find_common_root(package_or_module)
     cli_logger.debug(f"Using {detected_root} as root folder for project")
-    fast_serialization_settings = None
 
     # Create a zip file containing all the entries.
     zip_file = fast_package(detected_root, output, deref_symlinks)
     md5_bytes, _ = hash_file(pathlib.Path(zip_file))
 
+    fast_serialization_settings = None
     if non_fast is False:
         # Upload zip file to Admin using FlyteRemote.
         md5_bytes, native_url = remote._upload_file(pathlib.Path(zip_file))
@@ -194,5 +202,9 @@ def register(
         version = remote._version_from_hash(md5_bytes, serialization_settings, service_account, raw_data_prefix)  # noqa
         cli_logger.info(f"Computed version is {version}")
 
+    click.echo(
+        f"Registering entities under version {version} using the following serialization settings = {serialization_settings}"
+    )
+
     # Register using repo code
     repo_register(registerable_entities, project, domain, version, remote.client)
diff --git a/flytekit/clis/sdk_in_container/run.py b/flytekit/clis/sdk_in_container/run.py
index d0b890ba7b..7d7e1e3e2f 100644
--- a/flytekit/clis/sdk_in_container/run.py
+++ b/flytekit/clis/sdk_in_container/run.py
@@ -6,7 +6,7 @@
 import os
 import pathlib
 import typing
-from dataclasses import dataclass, replace
+from dataclasses import dataclass
 from typing import cast
 
 import click
@@ -22,7 +22,11 @@
     CTX_PROJECT,
     CTX_PROJECT_ROOT,
 )
-from flytekit.clis.sdk_in_container.helpers import FLYTE_REMOTE_INSTANCE_KEY, get_and_save_remote_with_click_context
+from flytekit.clis.sdk_in_container.helpers import (
+    FLYTE_REMOTE_INSTANCE_KEY,
+    get_and_save_remote_with_click_context,
+    patch_image_config,
+)
 from flytekit.configuration import ImageConfig
 from flytekit.configuration.default_images import DefaultImages
 from flytekit.core import context_manager
@@ -517,27 +521,8 @@ def _run(*args, **kwargs):
         remote = ctx.obj[FLYTE_REMOTE_INSTANCE_KEY]
         config_file = ctx.obj.get(CTX_CONFIG_FILE)
 
-        # Images come from three places:
-        # * The default flytekit images, which are already supplied by the base run_level_params.
-        # * The images provided by the user on the command line.
-        # * The images provided by the user via the config file, if there is one. (Images on the command line should
-        #   override all).
-        #
-        # However, the run_level_params already contains both the default flytekit images (lowest priority), as well
-        # as the images from the command line (highest priority). So when we read from the config file, we only
-        # want to add in the images that are missing, including the default, if that's also missing.
-        image_config_from_parent_cmd = run_level_params.get("image_config", None)
-        additional_image_names = set([v.name for v in image_config_from_parent_cmd.images])
-        new_additional_images = [v for v in image_config_from_parent_cmd.images]
-        new_default = image_config_from_parent_cmd.default_image
-        if config_file:
-            cfg_ic = ImageConfig.auto(config_file=config_file)
-            new_default = new_default or cfg_ic.default_image
-            for addl in cfg_ic.images:
-                if addl.name not in additional_image_names:
-                    new_additional_images.append(addl)
-
-        image_config = replace(image_config_from_parent_cmd, default_image=new_default, images=new_additional_images)
+        image_config = run_level_params.get("image_config")
+        image_config = patch_image_config(config_file, image_config)
 
         remote_entity = remote.register_script(
             entity,
diff --git a/tests/flytekit/unit/cli/pyflyte/test_register.py b/tests/flytekit/unit/cli/pyflyte/test_register.py
index e9661dff6a..05660aa054 100644
--- a/tests/flytekit/unit/cli/pyflyte/test_register.py
+++ b/tests/flytekit/unit/cli/pyflyte/test_register.py
@@ -79,6 +79,26 @@ def test_non_fast_register(mock_client, mock_remote):
         with open(os.path.join("core", "sample.py"), "w") as f:
             f.write(sample_file_contents)
             f.close()
-        result = runner.invoke(pyflyte.main, ["register", "--non-fast", "core"])
+        result = runner.invoke(pyflyte.main, ["register", "--non-fast", "--version", "a-version", "core"])
         assert "Output given as None, using a temporary directory at" in result.output
         shutil.rmtree("core")
+
+
+@mock.patch("flytekit.clis.sdk_in_container.helpers.FlyteRemote", spec=FlyteRemote)
+@mock.patch("flytekit.clients.friendly.SynchronousFlyteClient", spec=SynchronousFlyteClient)
+def test_non_fast_register_require_version(mock_client, mock_remote):
+    mock_remote._client = mock_client
+    mock_remote.return_value._version_from_hash.return_value = "dummy_version_from_hash"
+    mock_remote.return_value._upload_file.return_value = "dummy_md5_bytes", "dummy_native_url"
+    runner = CliRunner()
+    with runner.isolated_filesystem():
+        out = subprocess.run(["git", "init"], capture_output=True)
+        assert out.returncode == 0
+        os.makedirs("core", exist_ok=True)
+        with open(os.path.join("core", "sample.py"), "w") as f:
+            f.write(sample_file_contents)
+            f.close()
+        result = runner.invoke(pyflyte.main, ["register", "--non-fast", "core"])
+        assert result.exit_code == 1
+        assert str(result.exception) == "Version is a required parameter in case --non-fast is specified."
+        shutil.rmtree("core")