diff --git a/kernel/arm64/sgemm_tcopy_16.S b/kernel/arm64/sgemm_tcopy_16.S
index 46198b3a2..431f1ae2a 100644
--- a/kernel/arm64/sgemm_tcopy_16.S
+++ b/kernel/arm64/sgemm_tcopy_16.S
@@ -30,7 +30,7 @@ All rights reserved.
 #define	B00		x22
 
 
-#define I		x18
+#define I		x21
 #define	J		x19
 
 #define TEMP1		x20