diff --git a/src/kegstandcli/cli/config.py b/src/kegstandcli/cli/config.py
index 5071512..1b603ff 100644
--- a/src/kegstandcli/cli/config.py
+++ b/src/kegstandcli/cli/config.py
@@ -35,7 +35,7 @@ def find_config_file(verbose: bool, config_file: str | None) -> str | None:  # n
     return config_file
 
 
-def get_kegstand_config(verbose: bool, project_dir: str, config_file: str) -> dict[str, Any]:
+def get_kegstand_config(verbose: bool, project_dir: str, config_file: str) -> dict[str, Any]:  # noqa: PLR0912
     """Load and parse the Kegstand configuration.
 
     Args:
@@ -58,15 +58,23 @@ def get_kegstand_config(verbose: bool, project_dir: str, config_file: str) -> di
     # If the config file is pyproject.toml, the config will be under the 'tool.kegstand' key
     if config_file.endswith("pyproject.toml"):
         config = parsed_toml_config.get("tool", {}).get("kegstand", {})
-        # Some keys are used from the [project] section if not specified in [tool.kegstand]
+        # Some keys are used from the [project] or [tool.poetry] section
+        # if not specified in [tool.kegstand]
         properties_from_pyproject = ["name", "description", "version"]
         if "project" not in config:
             config["project"] = {}
         for property_name in properties_from_pyproject:
             if property_name not in config["project"]:
-                config["project"][property_name] = parsed_toml_config.get("project", {}).get(
-                    property_name
-                )
+                # Try to get the property from the [project] section
+                if property_name in parsed_toml_config.get("project", {}):
+                    config["project"][property_name] = parsed_toml_config.get("project", {}).get(
+                        property_name
+                    )
+                # Try to get the property from the [tool.poetry] section
+                elif property_name in parsed_toml_config.get("tool", {}).get("poetry", {}):
+                    config["project"][property_name] = (
+                        parsed_toml_config.get("tool", {}).get("poetry", {}).get(property_name)
+                    )
     else:
         config = parsed_toml_config
 
@@ -81,7 +89,9 @@ def get_kegstand_config(verbose: bool, project_dir: str, config_file: str) -> di
     config["config_file"] = str(config_path)
 
     # Set defaults where missing
-    config_defaults = {"api": {"name": "Untitled API", "entrypoint": "api.lambda.handler"}}
+    config_defaults = {
+        "api": {"name": "Untitled API", "entrypoint": "api.lambda.handler", "runtime": "python3.13"}
+    }
     for section, defaults in config_defaults.items():
         if section not in config:
             config[section] = {}
diff --git a/src/kegstandcli/infra/stacks/rest_api_backend.py b/src/kegstandcli/infra/stacks/rest_api_backend.py
index 87026a1..d9c50ed 100644
--- a/src/kegstandcli/infra/stacks/rest_api_backend.py
+++ b/src/kegstandcli/infra/stacks/rest_api_backend.py
@@ -10,7 +10,7 @@
 from aws_cdk import aws_lambda as lambda_
 from constructs import Construct
 
-from kegstandcli.utils import find_resource_modules
+from kegstandcli.utils import LambdaRuntime, find_resource_modules
 
 MODULE_CONFIG_KEY = "api"
 
@@ -66,7 +66,7 @@ def __init__(
             self,
             f"{construct_id}-Backend",
             function_name=f"{construct_id}-Function",
-            runtime=lambda_.Runtime.PYTHON_3_9,
+            runtime=LambdaRuntime(config[MODULE_CONFIG_KEY]["runtime"]).to_lambda_runtime(),
             handler=config[MODULE_CONFIG_KEY]["entrypoint"],
             code=lambda_.Code.from_asset(str(api_src_path)),
             layers=[  # See Lambda Powertools: https://awslabs.github.io/aws-lambda-powertools-python/2.4.0/
diff --git a/src/kegstandcli/utils.py b/src/kegstandcli/utils.py
index d7432b3..cb74263 100644
--- a/src/kegstandcli/utils.py
+++ b/src/kegstandcli/utils.py
@@ -5,6 +5,7 @@
 from typing import Any
 
 import click
+from aws_cdk import aws_lambda as lambda_
 from tomlkit import loads as parse_toml
 
 
@@ -18,6 +19,26 @@ def __str__(self) -> str:
         return self.value
 
 
+class LambdaRuntime(str, PythonEnum):
+    """Lambda runtime types."""
+
+    PYTHON_3_10 = "python3.10"
+    PYTHON_3_11 = "python3.11"
+    PYTHON_3_12 = "python3.12"
+    PYTHON_3_13 = "python3.13"
+
+    def __str__(self) -> str:
+        return self.value
+
+    def to_lambda_runtime(self) -> lambda_.Runtime:
+        return {
+            LambdaRuntime.PYTHON_3_10: lambda_.Runtime.PYTHON_3_10,
+            LambdaRuntime.PYTHON_3_11: lambda_.Runtime.PYTHON_3_11,
+            LambdaRuntime.PYTHON_3_12: lambda_.Runtime.PYTHON_3_12,
+            LambdaRuntime.PYTHON_3_13: lambda_.Runtime.PYTHON_3_13,
+        }[self]
+
+
 def find_resource_modules(api_src_dir: str) -> list[dict[str, Any]]:
     """Find API resource modules in the source directory.
 
diff --git a/uv.lock b/uv.lock
index 19137cf..a578909 100644
--- a/uv.lock
+++ b/uv.lock
@@ -446,7 +446,7 @@ wheels = [
 
 [[package]]
 name = "kegstandcli"
-version = "0.4.0"
+version = "0.4.1"
 source = { editable = "." }
 dependencies = [
     { name = "aws-cdk-lib" },