diff --git a/exec.c b/exec.c
index 63caca0..2e7434e 100644
--- a/exec.c
+++ b/exec.c
@@ -1623,6 +1623,7 @@ const CPULogItem cpu_log_items[] = {
     { 0, NULL, NULL },
 };
 
+#ifndef CONFIG_USER_ONLY
 static QLIST_HEAD(memory_client_list, CPUPhysMemoryClient) memory_client_list
     = QLIST_HEAD_INITIALIZER(memory_client_list);
 
@@ -1715,6 +1716,7 @@ void cpu_unregister_phys_memory_client(CPUPhysMemoryClient *client)
 {
     QLIST_REMOVE(client, list);
 }
+#endif
 
 static int cmp1(const char *s1, int n, const char *s2)
 {