diff --git a/arch/s390/kernel/runtime_instr.c b/arch/s390/kernel/runtime_instr.c
index 125c7f6e8715..1788a5454b6f 100644
--- a/arch/s390/kernel/runtime_instr.c
+++ b/arch/s390/kernel/runtime_instr.c
@@ -57,7 +57,7 @@ static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
 	cb->k = 1;
 	cb->ps = 1;
 	cb->pc = 1;
-	cb->key = PAGE_DEFAULT_KEY;
+	cb->key = PAGE_DEFAULT_KEY >> 4;
 	cb->v = 1;
 }