diff --git a/tests/t1_main.S b/tests/t1_main.S
index 1fa081576..eb3185978 100644
--- a/tests/t1_main.S
+++ b/tests/t1_main.S
@@ -4,6 +4,38 @@ _start:
     csrs mstatus, a0
     csrwi vcsr, 0
 
+    li x1, 0
+    li x2, 0
+    li x3, 0
+    li x4, 0
+    li x5, 0
+    li x6, 0
+    li x7, 0
+    li x8, 0
+    li x9, 0
+    li x10, 0
+    li x11, 0
+    li x12, 0
+    li x13, 0
+    li x14, 0
+    li x15, 0
+    li x16, 0
+    li x17, 0
+    li x18, 0
+    li x19, 0
+    li x20, 0
+    li x21, 0
+    li x22, 0
+    li x23, 0
+    li x24, 0
+    li x25, 0
+    li x26, 0
+    li x27, 0
+    li x28, 0
+    li x29, 0
+    li x30, 0
+    li x31, 0
+
     la sp, __stacktop
 
     // no ra to save