diff --git a/src/cmd/internal/obj/arm64/asm7.go b/src/cmd/internal/obj/arm64/asm7.go
index 178c83c0bc..bd2bd037ba 100644
--- a/src/cmd/internal/obj/arm64/asm7.go
+++ b/src/cmd/internal/obj/arm64/asm7.go
@@ -5338,10 +5338,10 @@ func (c *ctxt7) asmout(p *obj.Prog, o *Optab, out []uint32) {
 	// This is supposed to be something that stops execution.
 	// It's not supposed to be reached, ever, but if it is, we'd
 	// like to be able to tell how we got there. Assemble as
-	// 0xbea71700 which is guaranteed to raise undefined instruction
+	// UDF which is guaranteed to raise the undefined instruction
 	// exception.
 	case 90:
-		o1 = 0xbea71700
+		o1 = 0x0
 
 	case 91: /* prfm imm(Rn), <prfop | $imm5> */
 		imm := uint32(p.From.Offset)