diff --git a/tests/platform-matrix.rs b/tests/platform-matrix.rs
index 1f9f1cf..400e9e7 100644
--- a/tests/platform-matrix.rs
+++ b/tests/platform-matrix.rs
@@ -18,21 +18,22 @@ struct PlatformTest {
 
 fn read_manifest(host: &str, manifest_type: &str) -> Option<serde_json::Value> {
     let manifest_dir = Path::new("manifests");
-    // Find the most recent matching manifest
-    if let Ok(entries) = fs::read_dir(manifest_dir) {
-        for entry in entries.flatten() {
-            if let Ok(filename) = entry.file_name().into_string() {
-                if filename.contains(host) && filename.contains(manifest_type) {
-                    if let Ok(content) = fs::read_to_string(entry.path()) {
-                        if let Ok(json) = serde_json::from_str::<serde_json::Value>(&content) {
-                            return Some(json);
-                        }
-                    }
-                }
-            }
-        }
-    }
-    None
+    // Match the exact `<host>-<manifest_type>.json` suffix so a loose substring
+    // does not also grab a sibling like `…watchdog-host-status-run-manifest.json`
+    // (which has no `.status`). Collect all matches and pick the lexically
+    // greatest filename — dated `YYYY-MM-DD-` prefixes sort to "most recent" —
+    // so the result is deterministic regardless of `read_dir` ordering.
+    let suffix = format!("{}-{}.json", host, manifest_type);
+    let mut matches: Vec<_> = fs::read_dir(manifest_dir)
+        .ok()?
+        .flatten()
+        .filter_map(|entry| entry.file_name().into_string().ok().map(|n| (n, entry.path())))
+        .filter(|(name, _)| name.ends_with(&suffix))
+        .collect();
+    matches.sort_by(|a, b| a.0.cmp(&b.0));
+    let (_, path) = matches.last()?;
+    let content = fs::read_to_string(path).ok()?;
+    serde_json::from_str::<serde_json::Value>(&content).ok()
 }
 
 fn test_deepseek_cache_probe(platform: &str, host: &str) -> PlatformTest {