diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
index 2eb18f91..cb238747 100644
--- a/.github/pull_request_template.md
+++ b/.github/pull_request_template.md
@@ -52,4 +52,4 @@ If manual testing was performed, describe the testing process and results.
 ## Checklist
 
 - [ ] Architecture/docs impact considered. Updated `ARCHITECTURE.md`, developer docs,
-      and/or ADRs where needed, or explained why not.
+      and/or ADRs where needed.
diff --git a/src/myna/core/components/component.py b/src/myna/core/components/component.py
index 624e6564..98b4db0a 100644
--- a/src/myna/core/components/component.py
+++ b/src/myna/core/components/component.py
@@ -65,11 +65,14 @@ def run_component(self):
                 if all(valid):
                     print(f"All output files are valid for step {self.name}.")
                 else:
-                    print(
-                        f"WARNING: Only found {sum(valid)} valid output files out of {len(output_files)}"
-                        + f" output files for step {self.name}. Expected output files:"
+                    message = (
+                        f"Only found {sum(valid)} valid output files out of "
+                        f"{len(output_files)} output files for step {self.name}. "
+                        "Expected output files:"
                     )
+                    print(f"ERROR: {message}")
                     [print("\t" + x) for x in output_files]
+                    raise RuntimeError(message)
             else:
                 print(
                     f"No execute command was specified for step {self.name}. The expected output files are:"
diff --git a/tests/test_workflow_context.py b/tests/test_workflow_context.py
index c0b1b5a9..213534b1 100644
--- a/tests/test_workflow_context.py
+++ b/tests/test_workflow_context.py
@@ -12,10 +12,13 @@
 import sys
 import types
 
+import pytest
+
 from myna.core.app.base import MynaApp
 from myna.core.components.component import Component
 import myna.core.components
 from myna.core.context import current_workflow_context, workflow_context
+from myna.core.files.file import File
 from myna.core.workflow.run import run
 
 
@@ -185,3 +188,60 @@ def run_component(self):
     ]
     for key in WORKFLOW_ENV_KEYS:
         assert key not in os.environ
+
+
+class MissingOutputFile(File):
+    """Output file type used to exercise run-time validation."""
+
+    def __init__(self, file):
+        super().__init__(file)
+        self.filetype = ".csv"
+
+    def file_is_valid(self):
+        return True
+
+
+def test_component_run_raises_when_execute_does_not_produce_output(
+    monkeypatch, tmp_path
+):
+    _clear_workflow_env(monkeypatch)
+    input_file = tmp_path / "input.yaml"
+    input_file.write_text(
+        "steps: []\ndata:\n  build:\n    name: build\nmyna: {}\n",
+        encoding="utf-8",
+    )
+    module_name = "myna.application.fakeapp.fakeclass.execute"
+    original_import_module = importlib.import_module
+
+    def execute():
+        return None
+
+    fake_module = types.SimpleNamespace(execute=execute)
+
+    def fake_find_spec(name):
+        if name == module_name:
+            return ModuleSpec(name, loader=None, origin="/tmp/execute.py")
+        return None
+
+    def fake_import_module(name):
+        if name == module_name:
+            return fake_module
+        return original_import_module(name)
+
+    monkeypatch.setattr(importlib.util, "find_spec", fake_find_spec)
+    monkeypatch.setattr(importlib, "import_module", fake_import_module)
+
+    component = Component()
+    component.name = "demo"
+    component.component_application = "fakeapp"
+    component.component_class = "fakeclass"
+    component.input_file = os.fspath(input_file)
+    component.data = {"build": {"name": "build"}}
+    component.output_requirement = MissingOutputFile
+    component.output_template = "result.csv"
+
+    with pytest.raises(
+        RuntimeError,
+        match="Only found 0 valid output files out of 1 output files for step demo",
+    ):
+        component.run_component()