diff --git a/server.js b/server.js
index 70aba62..cf2777a 100644
--- a/server.js
+++ b/server.js
@@ -553,12 +553,13 @@ const validateResultCache = new Map();
 const RESULT_CACHE_TTL = 15 * 60 * 1000; // 15 minutes
 function resultCacheGet(map, key) {
   const e = map.get(String(key));
-  if (e && (Date.now() - e.ts) < RESULT_CACHE_TTL) return e.data;
+  const ttl = e && e.ttl ? e.ttl : RESULT_CACHE_TTL;
+  if (e && (Date.now() - e.ts) < ttl) return e.data;
   return undefined;
 }
-function resultCacheSet(map, key, data) {
+function resultCacheSet(map, key, data, ttlMs) {
   if (map.size > 2000) map.delete(map.keys().next().value);
-  map.set(String(key), { data, ts: Date.now() });
+  map.set(String(key), { data, ts: Date.now(), ttl: ttlMs || RESULT_CACHE_TTL });
 }
 
 // ============================================================
@@ -3372,7 +3373,10 @@ const server = http.createServer(async (req, res) => {
           note: "left=upstream providers, right=downstream customers, uncertain=peers. Sorted by power score.",
         },
       };
-      resultCacheSet(validateResultCache, rawAsn, validateResult);
+      // Cache 0-prefix results only briefly (90s) — they may be due to temporary API failures
+      // Full results with prefixes are cached for the standard 15 minutes
+      const validateCacheTTL = allPrefixes.length === 0 ? 90 * 1000 : RESULT_CACHE_TTL;
+      resultCacheSet(validateResultCache, rawAsn, validateResult, validateCacheTTL);
       return res.end(JSON.stringify(validateResult, null, 2));
     } catch (err) {
       res.writeHead(500);