diff --git a/sm4/gcm_arm64.s b/sm4/gcm_arm64.s
index 298d2b7..40bef73 100644
--- a/sm4/gcm_arm64.s
+++ b/sm4/gcm_arm64.s
@@ -160,7 +160,7 @@ TEXT ·gcmSm4Init(SB),NOSPLIT,$0
 #define I R2
 
 	MOVD productTable+0(FP), pTbl
-	MOVD src+8(FP), SRC
+	MOVD rk+8(FP), RK
 
 	MOVD	$0xC2, I
 	LSL	$56, I