diff --git a/hw/core/machine.c b/hw/core/machine.c
index 9e8c06036f..4778bc6b08 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -425,6 +425,14 @@ static void machine_set_memory_encryption(Object *obj, const char *value,
 
     g_free(ms->memory_encryption);
     ms->memory_encryption = g_strdup(value);
+
+    /*
+     * With memory encryption, the host can't see the real contents of RAM,
+     * so there's no point in it trying to merge areas.
+     */
+    if (value) {
+        machine_set_mem_merge(obj, false, errp);
+    }
 }
 
 static bool machine_get_nvdimm(Object *obj, Error **errp)