diff --git a/src/ast.rs b/src/ast.rs
index cf4a49ea..36232e76 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -106,7 +106,8 @@ pub struct Rule {
 /// Exactly one variant must be provided for a rule or target. The fields are
 /// flattened in the manifest, so the presence of `command`, `script`, or `rule`
 /// determines the variant.
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Serialize)]
+#[serde(untagged)]
 pub enum Recipe {
     /// A single shell command.
     Command { command: String },
diff --git a/src/ir.rs b/src/ir.rs
index 296a2ef4..deb4eefd 100644
--- a/src/ir.rs
+++ b/src/ir.rs
@@ -341,10 +341,10 @@ fn find_cycle(targets: &HashMap<PathBuf, BuildEdge>) -> Option<Vec<PathBuf>> {
         states: &mut HashMap<PathBuf, VisitState>,
     ) -> Option<Vec<PathBuf>> {
         for dep in deps {
-            if targets.contains_key(dep)
-                && let Some(cycle) = visit(targets, dep, stack, states)
-            {
-                return Some(cycle);
+            if targets.contains_key(dep) {
+                if let Some(cycle) = visit(targets, dep, stack, states) {
+                    return Some(cycle);
+                }
             }
         }
         None
diff --git a/tests/ast_tests.rs b/tests/ast_tests.rs
index a5818d0a..8ad1cb29 100644
--- a/tests/ast_tests.rs
+++ b/tests/ast_tests.rs
@@ -1,8 +1,9 @@
-//! Unit tests for Netsuke manifest AST deserialisation.
+//! Unit tests for Netsuke manifest AST serialisation and deserialisation.
 
 use netsuke::{ast::*, manifest};
 use rstest::rstest;
 use semver::Version;
+use serde_yml::Value;
 
 /// Convenience wrapper around the library manifest parser for tests.
 fn parse_manifest(yaml: &str) -> anyhow::Result<NetsukeManifest> {
@@ -362,3 +363,18 @@ fn invalid_manifests_fail(#[case] file: &str) {
     let path = format!("tests/data/{file}");
     assert!(manifest::from_path(&path).is_err());
 }
+
+#[rstest]
+#[case(Recipe::Command { command: "echo".into() }, "command: echo")]
+#[case(Recipe::Script { script: "run".into() }, "script: run")]
+#[case(
+    Recipe::Rule {
+        rule: StringOrList::List(vec!["a".into(), "b".into()]),
+    },
+    concat!("rule:\n", "  - a\n", "  - b"),
+)]
+fn serialize_recipe_variants(#[case] recipe: Recipe, #[case] expected_yaml: &str) {
+    let actual: Value = serde_yml::to_value(&recipe).expect("serialize");
+    let expected: Value = serde_yml::from_str(expected_yaml).expect("yaml");
+    assert_eq!(actual, expected);
+}