diff --git a/osbuild/formats/v1.py b/osbuild/formats/v1.py
index b9b8522e..7c68948c 100644
--- a/osbuild/formats/v1.py
+++ b/osbuild/formats/v1.py
@@ -9,7 +9,7 @@ to fetch resources.
 """
 from typing import Dict
 from osbuild.meta import Index, ValidationResult
-from ..pipeline import Manifest, Pipeline, detect_host_runner
+from ..pipeline import BuildResult, Manifest, Pipeline, detect_host_runner
 
 
 VERSION = "1"
@@ -194,6 +194,16 @@ def load(description: Dict, index: Index) -> Manifest:
 def output(manifest: Manifest, res: Dict) -> Dict:
     """Convert a result into the v1 format"""
 
+    def result_for_stage(result: BuildResult):
+        return {
+            "id": result.id,
+            "type": result.name,
+            "success": result.success,
+            "error": result.error,
+            "output": result.output,
+            "metadata": result.metadata,
+        }
+
     def result_for_pipeline(pipeline):
         # The pipeline might not have been built one of its
         # dependencies, i.e. its build pipeline, failed to
@@ -211,7 +221,9 @@ def output(manifest: Manifest, res: Dict) -> Dict:
 
         stages = current.get("stages")
         if stages:
-            retval["stages"] = stages
+            retval["stages"] = [
+                result_for_stage(r) for r in stages
+            ]
         return retval
 
     result = result_for_pipeline(manifest["tree"])
@@ -226,7 +238,10 @@ def output(manifest: Manifest, res: Dict) -> Dict:
     if not current:
         return result
 
-    result["assembler"] = current["stages"][0]
+    # The assembler pipeline must have exactly one stage
+    # which is the v1 assembler
+    stage = current["stages"][0]
+    result["assembler"] = result_for_stage(stage)
     if not result["assembler"]["success"]:
         result["success"] = False
 
diff --git a/osbuild/formats/v2.py b/osbuild/formats/v2.py
index a90975e7..4a43ba81 100644
--- a/osbuild/formats/v2.py
+++ b/osbuild/formats/v2.py
@@ -395,10 +395,10 @@ def output(manifest: Manifest, res: Dict) -> Dict:
                 "type": "org.osbuild.error.stage",
                 "details": {
                     "stage": {
-                        "id": failed["id"],
-                        "type": failed["name"],
-                        "output": failed["output"],
-                        "error": failed["error"]
+                        "id": failed.id,
+                        "type": failed.name,
+                        "output": failed.output,
+                        "error": failed.error,
                     }
                 }
             }
@@ -415,10 +415,10 @@ def output(manifest: Manifest, res: Dict) -> Dict:
             data = {}
             r = res.get(p.id, {})
             for stage in r.get("stages", []):
-                md = stage.get("metadata")
+                md = stage.metadata
                 if not md:
                     continue
-                name = stage["name"]
+                name = stage.name
                 val = data.setdefault(name, {})
                 val.update(md)
 
@@ -433,14 +433,14 @@ def output(manifest: Manifest, res: Dict) -> Dict:
 
         for stage in r.get("stages", []):
             data = {
-                "id": stage["id"],
-                "type": stage["name"],
-                "output": stage["output"]
+                "id": stage.id,
+                "type": stage.name,
+                "output": stage.output,
             }
-            if not stage["success"]:
-                data["success"] = stage["success"]
-                if stage["error"]:
-                    data["error"] = stage["error"]
+            if not stage.success:
+                data["success"] = stage.success
+                if stage.error:
+                    data["error"] = stage.error
 
             log.append(data)
 
diff --git a/osbuild/pipeline.py b/osbuild/pipeline.py
index 8d8e0624..407a0816 100644
--- a/osbuild/pipeline.py
+++ b/osbuild/pipeline.py
@@ -333,7 +333,7 @@ class Pipeline:
 
                 monitor.result(r)
 
-            results["stages"].append(r.as_dict())
+            results["stages"].append(r)
             if not r.success:
                 cleanup(build_tree, tree)
                 results["success"] = False