diff --git a/pyproject.toml b/pyproject.toml
index f463c1f9c..2f5634499 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "truss"
-version = "0.9.56rc2"
+version = "0.9.56rc3"
 description = "A seamless bridge from model development to model delivery"
 license = "MIT"
 readme = "README.md"
diff --git a/truss/base/trt_llm_config.py b/truss/base/trt_llm_config.py
index aff9350f7..194adcec7 100644
--- a/truss/base/trt_llm_config.py
+++ b/truss/base/trt_llm_config.py
@@ -208,27 +208,28 @@ class TRTLLMConfiguration(BaseModel):
     def migrate_runtime_fields(cls, data: Any) -> Any:
         extra_runtime_fields = {}
         valid_build_fields = {}
-        for key, value in data.get("build").items():
-            if key in TrussTRTLLMBuildConfiguration.__annotations__:
-                valid_build_fields[key] = value
-            else:
-                if key in TrussTRTLLMRuntimeConfiguration.__annotations__:
-                    logger.warning(f"Found runtime.{key}: {value} in build config")
-                    extra_runtime_fields[key] = value
-        if extra_runtime_fields:
-            logger.warning(
-                f"Found extra fields {list(extra_runtime_fields.keys())} in build configuration, unspecified runtime fields will be configured using these values."
-                " This configuration of deprecated fields is scheduled for removal, please upgrade to the latest truss version and update configs according to https://docs.baseten.co/performance/engine-builder-config."
-            )
-            data.get("runtime").update(
-                {
-                    k: v
-                    for k, v in extra_runtime_fields.items()
-                    if k not in data.get("runtime")
-                }
-            )
-
-        data.update({"build": valid_build_fields})
+        if isinstance(data.get("build"), dict):
+            for key, value in data.get("build").items():
+                if key in TrussTRTLLMBuildConfiguration.__annotations__:
+                    valid_build_fields[key] = value
+                else:
+                    if key in TrussTRTLLMRuntimeConfiguration.__annotations__:
+                        logger.warning(f"Found runtime.{key}: {value} in build config")
+                        extra_runtime_fields[key] = value
+            if extra_runtime_fields:
+                logger.warning(
+                    f"Found extra fields {list(extra_runtime_fields.keys())} in build configuration, unspecified runtime fields will be configured using these values."
+                    " This configuration of deprecated fields is scheduled for removal, please upgrade to the latest truss version and update configs according to https://docs.baseten.co/performance/engine-builder-config."
+                )
+                data.get("runtime").update(
+                    {
+                        k: v
+                        for k, v in extra_runtime_fields.items()
+                        if k not in data.get("runtime")
+                    }
+                )
+            data.update({"build": valid_build_fields})
+            return data
         return data
 
     @property
diff --git a/truss/tests/trt_llm/test_trt_llm_config.py b/truss/tests/trt_llm/test_trt_llm_config.py
index 0c4daf930..e6a0578d1 100644
--- a/truss/tests/trt_llm/test_trt_llm_config.py
+++ b/truss/tests/trt_llm/test_trt_llm_config.py
@@ -1,9 +1,16 @@
 from truss.base.trt_llm_config import (
     TRTLLMConfiguration,
     TrussTRTLLMBatchSchedulerPolicy,
+    TrussTRTLLMBuildConfiguration,
+    TrussTRTLLMRuntimeConfiguration,
 )
 
 
+def test_trt_llm_config_init_from_pydantic_models(trtllm_config):
+    build_config = TrussTRTLLMBuildConfiguration(**trtllm_config["trt_llm"]["build"])
+    TRTLLMConfiguration(build=build_config, runtime=TrussTRTLLMRuntimeConfiguration())
+
+
 def test_trt_llm_configuration_init_and_migrate_deprecated_runtime_fields(
     deprecated_trtllm_config,
 ):