diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index 1688bb246..b724d466d 100644
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -466,7 +466,7 @@ static void gen_wsr_windowbase(DisasContext *dc, uint32_t sr, TCGv_i32 v)
 
 static void gen_wsr_windowstart(DisasContext *dc, uint32_t sr, TCGv_i32 v)
 {
-    tcg_gen_mov_i32(cpu_SR[sr], v);
+    tcg_gen_andi_i32(cpu_SR[sr], v, (1 << dc->config->nareg / 4) - 1);
     reset_used_window(dc);
 }