diff --git a/kernel/apk_sign.c b/kernel/apk_sign.c
index 3307b576..a3589dcd 100644
--- a/kernel/apk_sign.c
+++ b/kernel/apk_sign.c
@@ -133,7 +133,7 @@ static bool check_block(struct file *fp, u32 *size4, loff_t *pos, u32 *offset, i
 		}
 		ksu_kernel_read_compat(fp, cert, *size4, pos);
 		unsigned char digest[SHA256_DIGEST_SIZE];
-		if (IS_ERR(ksu_sha256(cert, *size4, digest))) {
+		if (ksu_sha256(cert, *size4, digest) < 0 ) {
 			pr_info("sha256 error\n");
 			return false;
 		}