diff --git a/pmb/helpers/http.py b/pmb/helpers/http.py
index 7cecf313..99039432 100644
--- a/pmb/helpers/http.py
+++ b/pmb/helpers/http.py
@@ -38,6 +38,10 @@ def download(args, url, prefix, cache=True, loglevel=logging.INFO,
             return path
         pmb.helpers.run.user(args, ["rm", path])
 
+    # Offline and not cached
+    if args.offline:
+        raise RuntimeError(f"File not found in cache and offline flag is enabled: {url}")
+
     # Download the file
     logging.log(loglevel, "Download " + url)
     try: