diff --git a/Android.mk b/Android.mk
index 54f3632db..f8da48839 100644
--- a/Android.mk
+++ b/Android.mk
@@ -212,7 +212,6 @@ LOCAL_SRC_FILES                                          := \
     src/posix/platform/radio_spinel.cpp                     \
     src/posix/platform/random.c                             \
     src/posix/platform/settings.cpp                         \
-    src/posix/platform/spi-stubs.c                          \
     src/posix/platform/system.c                             \
     src/posix/platform/uart.c                               \
     third_party/mbedtls/repo/library/md.c                   \
diff --git a/src/posix/platform/Makefile.am b/src/posix/platform/Makefile.am
index 1265a91ee..fe5acf62f 100644
--- a/src/posix/platform/Makefile.am
+++ b/src/posix/platform/Makefile.am
@@ -48,7 +48,6 @@ libopenthread_posix_a_SOURCES             = \
     radio_spinel.cpp                        \
     random.c                                \
     settings.cpp                            \
-    spi-stubs.c                             \
     sim.c                                   \
     system.c                                \
     uart.c                                  \
diff --git a/src/posix/platform/spi-stubs.c b/src/posix/platform/spi-stubs.c
deleted file mode 100644
index 496debb38..000000000
--- a/src/posix/platform/spi-stubs.c
+++ /dev/null
@@ -1,94 +0,0 @@
-/*
- *  Copyright (c) 2016, The OpenThread Authors.
- *  All rights reserved.
- *
- *  Redistribution and use in source and binary forms, with or without
- *  modification, are permitted provided that the following conditions are met:
- *  1. Redistributions of source code must retain the above copyright
- *     notice, this list of conditions and the following disclaimer.
- *  2. Redistributions in binary form must reproduce the above copyright
- *     notice, this list of conditions and the following disclaimer in the
- *     documentation and/or other materials provided with the distribution.
- *  3. Neither the name of the copyright holder nor the
- *     names of its contributors may be used to endorse or promote products
- *     derived from this software without specific prior written permission.
- *
- *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- *  POSSIBILITY OF SUCH DAMAGE.
- */
-
-/**
- * @file
- *   This file implements the spi stubs.
- *
- */
-
-#include "openthread-core-config.h"
-#include "platform-posix.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <openthread/config.h>
-#include <openthread/platform/spi-slave.h>
-#include <openthread/platform/uart.h>
-
-#if OPENTHREAD_ENABLE_NCP_SPI
-
-// Spi-slave stubs
-
-otError otPlatSpiSlaveEnable(otPlatSpiSlaveTransactionCompleteCallback aCompleteCallback,
-                             otPlatSpiSlaveTransactionProcessCallback  aProcessCallback,
-                             void *                                    aContext)
-{
-    OT_UNUSED_VARIABLE(aCompleteCallback);
-    OT_UNUSED_VARIABLE(aProcessCallback);
-    OT_UNUSED_VARIABLE(aContext);
-
-    fprintf(stderr, "\nNo SPI support for posix platform.");
-    exit(OT_EXIT_FAILURE);
-
-    return OT_ERROR_NOT_IMPLEMENTED;
-}
-
-void otPlatSpiSlaveDisable(void)
-{
-}
-
-otError otPlatSpiSlavePrepareTransaction(uint8_t *aOutputBuf,
-                                         uint16_t aOutputBufLen,
-                                         uint8_t *aInputBuf,
-                                         uint16_t aInputBufLen,
-                                         bool     aRequestTransactionFlag)
-{
-    OT_UNUSED_VARIABLE(aOutputBuf);
-    OT_UNUSED_VARIABLE(aOutputBufLen);
-    OT_UNUSED_VARIABLE(aInputBuf);
-    OT_UNUSED_VARIABLE(aInputBufLen);
-    OT_UNUSED_VARIABLE(aRequestTransactionFlag);
-
-    return OT_ERROR_NOT_IMPLEMENTED;
-}
-
-// Uart
-
-void otPlatUartSendDone(void)
-{
-}
-
-void otPlatUartReceived(const uint8_t *aBuf, uint16_t aBufLength)
-{
-    OT_UNUSED_VARIABLE(aBuf);
-    OT_UNUSED_VARIABLE(aBufLength);
-}
-
-#endif // OPENTHREAD_ENABLE_NCP_SPI