diff --git a/plugin/builder/image_builder.py b/plugin/builder/image_builder.py
index 116b4dc..e0591d4 100644
--- a/plugin/builder/image_builder.py
+++ b/plugin/builder/image_builder.py
@@ -109,6 +109,28 @@ def target_repo(topdir, target_info, repo_info):
     return f"{repo}/$arch"
 
 
+def load_rpmlist_from_output(output_dir):
+    """Load *.rpmlist.json files written by image-builder-cli --with-rpmlist.
+    """
+
+    rpmlist = []
+    if not os.path.isdir(output_dir):
+        return rpmlist
+
+    for root, _, files in os.walk(output_dir):
+        for file in files:
+            if not file.endswith(".rpmlist.json"):
+                continue
+            path = os.path.join(root, file)
+            try:
+                with open(path, "r", encoding="utf-8") as f:
+                    rpmlist.extend(json.load(f))
+            except (OSError, UnicodeError, json.JSONDecodeError) as e:
+                logger.warning("skipped rpmlist %s: %s", path, e)
+
+    return rpmlist
+
+
 class ImageBuilderBuildTask(BuildImageTask):
     """Spawns imageBuilderBuildArch tasks."""
 
@@ -421,6 +443,7 @@ def handler(
             [
                 "--with-sbom",
                 "--with-manifest",
+                "--with-rpmlist",
             ]
         )
 
@@ -504,6 +527,12 @@ def handler(
                 self.uploadFile(os.path.join(root, file), remoteName=file)
                 data["files"].append(file)
 
+        # Only do the hdrlist when this is a non-scratch build
+        if not self.opts.get("scratch"):
+            rpmlist = load_rpmlist_from_output(output)
+            broot.markExternalRPMs(rpmlist)
+            data["rpmlist"] = rpmlist
+
         broot.expire()
 
         return data
diff --git a/test/conftest.py b/test/conftest.py
index 3fd4c0c..0266052 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -32,6 +32,9 @@ def mock(self, args):
 
         return 0
 
+    def markExternalRPMs(self, args, **kwargs):
+        pass
+
 
 @pytest.fixture
 def koji_mock_kojid(mocker, tmpdir):
diff --git a/test/unit/test_builder.py b/test/unit/test_builder.py
index 6c4ae3e..9496ad3 100644
--- a/test/unit/test_builder.py
+++ b/test/unit/test_builder.py
@@ -53,6 +53,7 @@ def test_build_arch_task(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--output-dir",
             "/builddir/output",
             "--output-name",
@@ -101,6 +102,7 @@ def test_build_arch_task_with_repos(koji_mock_kojid):
             "c/x86_64/d",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--output-dir",
             "/builddir/output",
             "--output-name",
@@ -147,6 +149,7 @@ def test_build_arch_task_multiple_types(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--output-dir",
             "/builddir/output",
             "--output-name",
@@ -168,6 +171,7 @@ def test_build_arch_task_multiple_types(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--output-dir",
             "/builddir/output",
             "--output-name",
@@ -220,6 +224,7 @@ def test_build_arch_task_ostree(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--ostree-url",
             "https://kojipkgs.fedoraproject.org/compose/iot/repo/",
             "--ostree-ref",
@@ -297,6 +302,7 @@ def test_build_arch_task_seed(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--seed", "1234",
             "--output-dir",
             "/builddir/output",
@@ -347,6 +353,7 @@ def test_build_arch_task_preview(koji_mock_kojid):
             "//repos/f42-build/1/$arch",
             "--with-sbom",
             "--with-manifest",
+            "--with-rpmlist",
             "--preview", "false",
             "--output-dir",
             "/builddir/output",
@@ -357,3 +364,22 @@ def test_build_arch_task_preview(koji_mock_kojid):
     ]
 
 
+def test_load_rpmlist_from_output_missing(koji_mock_kojid, tmp_path):
+    import plugin.builder.image_builder as builder
+
+    missing = tmp_path / "not-a-dir"
+    assert builder.load_rpmlist_from_output(str(missing)) == []
+
+
+def test_load_rpmlist_from_output(koji_mock_kojid, tmp_path):
+    import plugin.builder.image_builder as builder
+
+    out = tmp_path / "output"
+    out.mkdir()
+    (out / "img.rpmlist.json").write_text(
+        '[{"name":"mpfr","version":"4.1.0","release":"10.el9","epoch":0,"arch":"x86_64","buildtime":1770637270,"size":331788,"payloadhash":"11c1d6b33b7e64ddc40faf45b949618c829bd2e3d3661132417e4c8aee6ab0fd"}]',
+        encoding="utf-8",
+    )
+    assert builder.load_rpmlist_from_output(str(out)) == [
+        {"name":"mpfr","version":"4.1.0","release":"10.el9","epoch":0,"arch":"x86_64","buildtime":1770637270,"size":331788,"payloadhash":"11c1d6b33b7e64ddc40faf45b949618c829bd2e3d3661132417e4c8aee6ab0fd"},
+    ]