diff --git a/src/org/forkalsrud/album/web/AlbumServlet.java b/src/org/forkalsrud/album/web/AlbumServlet.java
index afb6f1c..4c02042 100644
--- a/src/org/forkalsrud/album/web/AlbumServlet.java
+++ b/src/org/forkalsrud/album/web/AlbumServlet.java
@@ -69,7 +69,7 @@ public class AlbumServlet
         if (pathInfo != null && pathInfo.startsWith(basePrefix)) {
         	pathInfo = pathInfo.substring(basePrefix.length());
         } else {
-        	res.sendError(HttpServletResponse.SC_NOT_FOUND);
+        	res.sendError(HttpServletResponse.SC_NOT_FOUND, "pathinfo=" + pathInfo);
         	return;
         }
 
@@ -153,12 +153,14 @@ public class AlbumServlet
 
         if (notModified(req, file)) {
             res.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+            res.setDateHeader("Expires", System.currentTimeMillis() + (30 * 24 * 3600 * 1000)); // 30 days
             System.out.println(file.getName() + " not modified (based on date)");
             return;
         }
         String fileEtag = thumbnail.getEtag() + "-" + size;
         if (etagMatches(req, fileEtag)) {
             res.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
+            res.setDateHeader("Expires", System.currentTimeMillis() + (30 * 24 * 3600 * 1000)); // 30 days
             System.out.println(file.getName() + " not modified (based on etag)");
             return;
         }
@@ -195,6 +197,7 @@ public class AlbumServlet
         res.setStatus(HttpServletResponse.SC_OK);
         res.setDateHeader("Last-Modified", file.lastModified());
         res.setHeader("ETag", fileEtag);
+        res.setDateHeader("Expires", System.currentTimeMillis() + (30 * 24 * 3600 * 1000)); // 30 days
         res.setContentType(cimg.mimeType);
         res.setContentLength(cimg.bits.length);
         res.getOutputStream().write(cimg.bits);