diff --git a/buildrunner/docker/__init__.py b/buildrunner/docker/__init__.py
index d7267e6..09e6843 100644
--- a/buildrunner/docker/__init__.py
+++ b/buildrunner/docker/__init__.py
@@ -107,7 +107,9 @@ def force_remove_container(docker_client, container):
     )
 
 
-def get_dockerfile(dockerfile: str, temp_dir: str = None) -> Tuple[str, bool]:
+def get_dockerfile(
+    dockerfile: str, temp_dir: str = None, path: str = None
+) -> Tuple[str, bool]:
     """
     Check if the dockerfile exists, if not create a temporary file and write the dockerfile to it.
     :param dockerfile: the dockerfile
@@ -117,7 +119,19 @@ def get_dockerfile(dockerfile: str, temp_dir: str = None) -> Tuple[str, bool]:
     cleanup_dockerfile = False
     curr_dockerfile = None
 
-    if dockerfile:
+    if path and path != "." and not dockerfile:
+        if os.path.exists(path):
+            if os.path.exists(os.path.join(path, "Dockerfile")):
+                curr_dockerfile = os.path.join(path, "Dockerfile")
+            else:
+                raise BuildRunnerConfigurationError(
+                    f"Path {path} exists but does not contain a Dockerfile"
+                )
+        else:
+            raise BuildRunnerConfigurationError(
+                f"Path {path} does not exist, cannot find Dockerfile"
+            )
+    elif dockerfile:
         if os.path.exists(dockerfile):
             curr_dockerfile = dockerfile
         else:
diff --git a/buildrunner/docker/multiplatform_image_builder.py b/buildrunner/docker/multiplatform_image_builder.py
index 82e42ee..58fed9b 100644
--- a/buildrunner/docker/multiplatform_image_builder.py
+++ b/buildrunner/docker/multiplatform_image_builder.py
@@ -429,7 +429,7 @@ def build_multiple_images(
             else:
                 path = "."
 
-        dockerfile, cleanup_dockerfile = get_dockerfile(file)
+        dockerfile, cleanup_dockerfile = get_dockerfile(dockerfile=file, path=path)
 
         # Track this newly built image
         built_image = BuiltImageInfo(id=str(uuid.uuid4()))
diff --git a/buildrunner/sshagent/__init__.py b/buildrunner/sshagent/__init__.py
index 7c04977..394056e 100644
--- a/buildrunner/sshagent/__init__.py
+++ b/buildrunner/sshagent/__init__.py
@@ -28,11 +28,12 @@
 from paramiko.util import asbytes
 from paramiko.message import Message
 
+import buildrunner.config
+import buildrunner.docker.builder as legacy_builder
 from buildrunner.errors import (
     BuildRunnerConfigurationError,
     BuildRunnerProcessingError,
 )
-import buildrunner.docker.builder as legacy_builder
 
 SSH_AGENT_PROXY_BUILD_CONTEXT = os.path.join(
     os.path.dirname(__file__), "SSHAgentProxyImage"
@@ -88,7 +89,9 @@ class DockerSSHAgentProxy:
     implementation that is managed by this class.
     """
 
-    def __init__(self, docker_client, log, docker_registry):
+    def __init__(
+        self, docker_client, log, docker_registry, multiplatform_image_builder
+    ):
         """ """
         self.docker_client = docker_client
         self.log = log
@@ -97,6 +100,7 @@ def __init__(self, docker_client, log, docker_registry):
         self._ssh_agent_container = None
         self._ssh_client = None
         self._ssh_channel = None
+        self._multiplatform_image_builder = multiplatform_image_builder
 
     def get_info(self):
         """
@@ -249,15 +253,33 @@ def get_ssh_agent_image(self):
         """
         Get and/or create the image used to proxy the ssh agent to a container.
         """
+        buildrunner_config = buildrunner.config.BuildRunnerConfig.get_instance()
         if not self._ssh_agent_image:
-            self.log.write("Creating ssh-agent image\n")
-            image = legacy_builder.build_image(
-                path=SSH_AGENT_PROXY_BUILD_CONTEXT,
-                docker_registry=self.docker_registry,
-                nocache=False,
-                pull=False,
-            )
-            self._ssh_agent_image = image
+            if buildrunner_config.run_config.use_legacy_builder:
+                self.log.write("Creating ssh-agent image\n")
+                image = legacy_builder.build_image(
+                    path=SSH_AGENT_PROXY_BUILD_CONTEXT,
+                    docker_registry=self.docker_registry,
+                    nocache=False,
+                    pull=False,
+                )
+                self._ssh_agent_image = image
+            else:
+                native_platform = (
+                    self._multiplatform_image_builder.get_native_platform()
+                )
+                platforms = [native_platform]
+                built_images_info = (
+                    self._multiplatform_image_builder.build_multiple_images(
+                        platforms=platforms,
+                        path=SSH_AGENT_PROXY_BUILD_CONTEXT,
+                        cache=False,
+                        pull=False,
+                        use_threading=False,
+                    )
+                )
+                assert len(built_images_info.built_images) == 1
+                self._ssh_agent_image = built_images_info.built_images[0].trunc_digest
         return self._ssh_agent_image
 
 
diff --git a/buildrunner/steprunner/tasks/run.py b/buildrunner/steprunner/tasks/run.py
index 618627a..c677b85 100644
--- a/buildrunner/steprunner/tasks/run.py
+++ b/buildrunner/steprunner/tasks/run.py
@@ -825,6 +825,7 @@ def run(self, context: dict):  # pylint: disable=too-many-statements,too-many-br
                 self._docker_client,
                 self.step_runner.log,
                 buildrunner_config.global_config.docker_registry,
+                self.step_runner.multi_platform,
             )
             self._sshagent.start(
                 buildrunner_config.get_ssh_keys_from_aliases(
diff --git a/setup.py b/setup.py
index 3df85fe..1b83eb5 100644
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,7 @@
 from setuptools import setup, find_packages
 
 
-BASE_VERSION = "3.12"
+BASE_VERSION = "3.13"
 
 SOURCE_DIR = os.path.dirname(os.path.abspath(__file__))
 BUILDRUNNER_DIR = os.path.join(SOURCE_DIR, "buildrunner")
diff --git a/tests/test-files/test-ssh-buildx.yaml b/tests/test-files/test-ssh-buildx.yaml
new file mode 100644
index 0000000..8bfb8c7
--- /dev/null
+++ b/tests/test-files/test-ssh-buildx.yaml
@@ -0,0 +1,17 @@
+use-legacy-builder: True
+steps:
+  clone:
+    build:
+      dockerfile: |
+        FROM {{ DOCKER_REGISTRY }}/rockylinux:8.5
+        RUN yum install -y git-core openssh-clients && yum clean all
+    run:
+      ssh-keys: ['buildrunner-deploy']
+      cmds:
+      - mkdir ~/.ssh
+      - ssh-keyscan github.com > ~/.ssh/known_hosts
+      - chmod 700 ~/.ssh
+      - chmod 600 ~/.ssh/known_hosts
+      # Clone into temp directory since the "buildrunner" directory may already exist
+      - rm -rf /tmp/test-clone
+      - git clone git@github.com:adobe/buildrunner.git /tmp/test-clone
diff --git a/tests/test_builders.py b/tests/test_builders.py
index a258d48..605ce49 100644
--- a/tests/test_builders.py
+++ b/tests/test_builders.py
@@ -56,10 +56,10 @@ def fixture_set_env():
 
 
 @pytest.mark.parametrize(
-    "use_legacy_builder, config,",
+    "description, use_legacy_builder, config,",
     [
-        # Use default builder
         (
+            "Use buildx builder with platform",
             False,
             """
             use-legacy-builder: false
@@ -74,6 +74,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Use buildx builder",
             False,
             """
             use-legacy-builder: false
@@ -87,6 +88,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Overwrite use-legacy-builder with platforms",
             False,
             """
             use-legacy-builder: true
@@ -103,6 +105,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Use buildx builder with platforms",
             False,
             """
             use-legacy-builder: false
@@ -119,6 +122,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Default builder with platforms",
             False,
             """
             steps:
@@ -133,8 +137,8 @@ def fixture_set_env():
                             - linux/arm64
             """,
         ),
-        # Use legacy builder
         (
+            "Default builder",
             True,
             """
             steps:
@@ -147,6 +151,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Use legacy builder with platform",
             True,
             """
             use-legacy-builder: true
@@ -161,6 +166,7 @@ def fixture_set_env():
             """,
         ),
         (
+            "Use legacy builder with use-legacy-builder",
             True,
             """
             use-legacy-builder: true
@@ -184,9 +190,11 @@ def fixture_set_env():
 def test_builders(
     mock_buildx_builder,
     mock_legacy_build,
+    description,
     use_legacy_builder,
     config,
 ):
+    _ = description
     with tempfile.TemporaryDirectory() as tmpdirname:
         tmp_filename = f"{tmpdirname}/config.yaml"
         with open(tmp_filename, "w") as f: