diff --git a/src/i2c.jl b/src/i2c.jl
index 4305907..a4ecc07 100644
--- a/src/i2c.jl
+++ b/src/i2c.jl
@@ -338,7 +338,7 @@ function i2c_read_block_data(self::Pi, handle, reg)
     # Don't raise exception.  Must release lock.
     bytes = u2i(_pigpio_command(self.sl, _PI_CMD_I2CRK, handle, reg, false))
     if bytes > 0
-        data = rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
@@ -614,7 +614,7 @@ function i2c_zip(self::Pi, handle, data)
     bytes = u2i(_pigpio_command_ext(
     self.sl, _PI_CMD_I2CZ, handle, 0, length(data), data, false))
     if bytes > 0
-        data = self._rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
@@ -756,7 +756,7 @@ function bb_i2c_zip(self::Pi, SDA, data)
     bytes = u2i(_pigpio_command_ext(
     self.sl, _PI_CMD_BI2CZ, SDA, 0, length(data), [data], false))
     if bytes > 0
-        data = self._rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
diff --git a/src/pi.jl b/src/pi.jl
index 355d56c..133dfd6 100644
--- a/src/pi.jl
+++ b/src/pi.jl
@@ -1218,7 +1218,7 @@ function custom_2(self, arg1=0, argx=[], retMax=8192)
     bytes = u2i(_pigpio_command_ext(
     self.sl, _PI_CMD_CF2, arg1, retMax, length(argx), [argx], false))
     if bytes > 0
-        data = rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
diff --git a/src/spiSerial.jl b/src/spiSerial.jl
index e93181b..15a45d9 100644
--- a/src/spiSerial.jl
+++ b/src/spiSerial.jl
@@ -132,7 +132,7 @@ function spi_read(self::Pi, handle, count)
     bytes = u2i(_pigpio_command(
     self.sl, _PI_CMD_SPIR, handle, count, false))
     if bytes > 0
-        data = rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
@@ -195,11 +195,14 @@ function spi_xfer(self::Pi, handle, data)
     ## extension ##
     # s len data bytes
 
+    # python code
+    # https://github.com/joan2937/pigpio/blob/c33738a320a3e28824af7807edafda440952c05d/pigpio.py#L4045
+
     # Don't raise exception.  Must release lock.
     bytes = u2i(_pigpio_command_ext(
     self.sl, _PI_CMD_SPIX, handle, 0, length(data), data, false))
     if bytes > 0
-        data = rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
@@ -306,7 +309,7 @@ function serial_read(self::Pi, handle, count)
     bytes = u2i(
     _pigpio_command(self.sl, _PI_CMD_SERR, handle, count, false))
     if bytes > 0
-        data = rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end
@@ -418,7 +421,7 @@ function bb_serial_read(self, user_gpio)
     bytes = u2i(
         _pigpio_command(self.sl, _PI_CMD_SLR, user_gpio, 10000, false))
     if bytes > 0
-        data = self._rxbuf(bytes)
+        data = rxbuf(self,bytes)
     else
         data = ""
     end