diff --git a/usr.sbin/i2c/i2c.c b/usr.sbin/i2c/i2c.c
index 3021b868e181..744fefc7121f 100644
--- a/usr.sbin/i2c/i2c.c
+++ b/usr.sbin/i2c/i2c.c
@@ -294,7 +294,8 @@ i2c_write(char *dev, struct options i2c_opt, char *i2c_buf)
 			err_msg = "error: offset malloc";
 			goto err1;
 		}
-	}
+	} else
+		bufsize = 0;
 
 	switch(i2c_opt.mode) {
 	case I2C_MODE_STOP_START: