diff --git a/server.go b/server.go
index 8222995..a4f1e5c 100644
--- a/server.go
+++ b/server.go
@@ -332,6 +332,7 @@ func (s *Server) InGroup(group, user string) bool {
 
 // fileOwnerGroup returns the uid and gid for a given path.
 // Session files are owned by the session's principal with group "agent".
+// Prompt library (/p/) is owned by "ollie" with group "user".
 // Everything else is owned by "ollie" with group "ollie".
 func (s *Server) fileOwnerGroup(path string) (uid, gid string) {
 	if strings.HasPrefix(path, "/s/") {
@@ -342,16 +343,19 @@ func (s *Server) fileOwnerGroup(path string) (uid, gid string) {
 			}
 		}
 	}
+	if path == "/p" || strings.HasPrefix(path, "/p/") {
+		return "ollie", "user"
+	}
 	return "ollie", "ollie"
 }
 
 // checkPerm verifies that uname has the requested access (mode) to path.
 // mode is the 9P open mode: OREAD=0, OWRITE=1, ORDWR=2, OEXEC=3.
-// Only enforced on session files (/s/{session_id}/...).
+// Enforced on session files and group-restricted paths (e.g. /p/).
 func (s *Server) checkPerm(uname, path string, mode uint8) error {
 	uid, gid := s.fileOwnerGroup(path)
-	if uid == "ollie" {
-		return nil // non-session files: no enforcement
+	if uid == "ollie" && gid == "ollie" {
+		return nil // no enforcement
 	}
 	dir := s.makeStat(path)
 	perm := uint32(dir.Mode) & 0777
@@ -1457,7 +1461,7 @@ func (s *Server) readDir(path string, offset uint64, count uint32) []byte {
 		dirs = append(dirs, makeDir("backends", "/backends", false, 0444))
 		dirs = append(dirs, makeDir("help", "/help", false, 0444))
 		dirs = append(dirs, makeDir("m", "/m", true, plan9.DMDIR|0755))
-		dirs = append(dirs, makeDir("p", "/p", true, plan9.DMDIR|0555))
+		dirs = append(dirs, makeDir("p", "/p", true, plan9.DMDIR|0750))
 		dirs = append(dirs, makeDir("s", "/s", true, plan9.DMDIR|0555))
 		dirs = append(dirs, makeDir("sk", "/sk", true, plan9.DMDIR|0555))
 		dirs = append(dirs, makeDir("tmp", "/tmp", true, plan9.DMDIR|0755))
@@ -1475,7 +1479,7 @@ func (s *Server) readDir(path string, offset uint64, count uint32) []byte {
 		entries, _ := s.promptStore.List()
 		for _, e := range entries {
 			if !e.IsDir() {
-				dirs = append(dirs, makeDir(e.Name(), "/p/"+e.Name(), false, 0666))
+				dirs = append(dirs, makeDir(e.Name(), "/p/"+e.Name(), false, 0640))
 			}
 		}
 	} else if path == "/m" {
@@ -1667,7 +1671,7 @@ func (s *Server) makeStat(path string) plan9.Dir {
 			} else if strings.HasPrefix(path, "/a/") {
 				mode = 0666
 			} else if strings.HasPrefix(path, "/p/") {
-				mode = 0444
+				mode = 0640
 			} else if strings.HasPrefix(path, "/m/") {
 				mode = 0666
 			} else if path == "/sk/idx" {