diff --git a/ChangeLog.d/add_mbedtls_setbuf.txt b/ChangeLog.d/add_mbedtls_setbuf.txt
new file mode 100644
index 000000000..d14cd18aa
--- /dev/null
+++ b/ChangeLog.d/add_mbedtls_setbuf.txt
@@ -0,0 +1,11 @@
+Security
+   * Add the platform function mbedtls_setbuf() to allow buffering to be
+     disabled on stdio files, to stop secrets loaded from said files being
+     potentially left in memory after file operations. Reported by
+     Glenn Strauss.
+Requirement changes
+   * The library will no longer compile out of the box on a platform without
+     setbuf(). If your platform does not have setbuf(), you can configure an
+     alternative function by enabling MBEDTLS_PLATFORM_SETBUF_ALT or
+     MBEDTLS_PLATFORM_SETBUF_MACRO.
+
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index bdc32e183..1c3d6ab40 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -385,6 +385,20 @@
 #error "MBEDTLS_PLATFORM_EXIT_MACRO and MBEDTLS_PLATFORM_STD_EXIT/MBEDTLS_PLATFORM_EXIT_ALT cannot be defined simultaneously"
 #endif
 
+#if defined(MBEDTLS_PLATFORM_SETBUF_ALT) && !defined(MBEDTLS_PLATFORM_C)
+#error "MBEDTLS_PLATFORM_SETBUF_ALT defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_SETBUF_MACRO) && !defined(MBEDTLS_PLATFORM_C)
+#error "MBEDTLS_PLATFORM_SETBUF_MACRO defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_SETBUF_MACRO) &&\
+    ( defined(MBEDTLS_PLATFORM_STD_SETBUF) ||\
+        defined(MBEDTLS_PLATFORM_SETBUF_ALT) )
+#error "MBEDTLS_PLATFORM_SETBUF_MACRO and MBEDTLS_PLATFORM_STD_SETBUF/MBEDTLS_PLATFORM_SETBUF_ALT cannot be defined simultaneously"
+#endif
+
 #if defined(MBEDTLS_PLATFORM_TIME_ALT) &&\
     ( !defined(MBEDTLS_PLATFORM_C) ||\
         !defined(MBEDTLS_HAVE_TIME) )
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 9c8ec11a7..060973f22 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -225,6 +225,7 @@
  * Uncomment a macro to enable alternate implementation of specific base
  * platform function
  */
+//#define MBEDTLS_PLATFORM_SETBUF_ALT
 //#define MBEDTLS_PLATFORM_EXIT_ALT
 //#define MBEDTLS_PLATFORM_TIME_ALT
 //#define MBEDTLS_PLATFORM_FPRINTF_ALT
@@ -3318,6 +3319,7 @@
 //#define MBEDTLS_PLATFORM_STD_MEM_HDR   <stdlib.h> /**< Header to include if MBEDTLS_PLATFORM_NO_STD_FUNCTIONS is defined. Don't define if no header is needed. */
 //#define MBEDTLS_PLATFORM_STD_CALLOC        calloc /**< Default allocator to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_FREE            free /**< Default free to use, can be undefined */
+//#define MBEDTLS_PLATFORM_STD_SETBUF      setbuf /**< Default setbuf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT            exit /**< Default exit to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_TIME            time /**< Default time to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 //#define MBEDTLS_PLATFORM_STD_FPRINTF      fprintf /**< Default fprintf to use, can be undefined */
@@ -3335,6 +3337,7 @@
 //#define MBEDTLS_PLATFORM_CALLOC_MACRO        calloc /**< Default allocator macro to use, can be undefined */
 //#define MBEDTLS_PLATFORM_FREE_MACRO            free /**< Default free macro to use, can be undefined */
 //#define MBEDTLS_PLATFORM_EXIT_MACRO            exit /**< Default exit macro to use, can be undefined */
+//#define MBEDTLS_PLATFORM_SETBUF_MACRO      setbuf /**< Default setbuf macro to use, can be undefined */
 //#define MBEDTLS_PLATFORM_TIME_MACRO            time /**< Default time macro to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 //#define MBEDTLS_PLATFORM_TIME_TYPE_MACRO       time_t /**< Default time macro to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
 //#define MBEDTLS_PLATFORM_FPRINTF_MACRO      fprintf /**< Default fprintf macro to use, can be undefined */
diff --git a/include/mbedtls/platform.h b/include/mbedtls/platform.h
index a5984345b..a5a43ac6d 100644
--- a/include/mbedtls/platform.h
+++ b/include/mbedtls/platform.h
@@ -91,6 +91,9 @@ extern "C" {
 #if !defined(MBEDTLS_PLATFORM_STD_FREE)
 #define MBEDTLS_PLATFORM_STD_FREE       free /**< The default \c free function to use. */
 #endif
+#if !defined(MBEDTLS_PLATFORM_STD_SETBUF)
+#define MBEDTLS_PLATFORM_STD_SETBUF   setbuf /**< The default \c setbuf function to use. */
+#endif
 #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
 #define MBEDTLS_PLATFORM_STD_EXIT      exit /**< The default \c exit function to use. */
 #endif
@@ -276,6 +279,56 @@ int mbedtls_platform_set_vsnprintf( int (*vsnprintf_func)( char * s, size_t n,
 #endif /* MBEDTLS_PLATFORM_VSNPRINTF_MACRO */
 #endif /* MBEDTLS_PLATFORM_VSNPRINTF_ALT */
 
+/*
+ * The function pointers for setbuf
+ */
+#if defined(MBEDTLS_PLATFORM_SETBUF_ALT)
+#include <stdio.h>
+/**
+ * \brief                  Function pointer to call for `setbuf()` functionality
+ *                         (changing the internal buffering on stdio calls).
+ *
+ * \note                   The library calls this function to disable
+ *                         buffering when reading or writing sensitive data,
+ *                         to avoid having extra copies of sensitive data
+ *                         remaining in stdio buffers after the file is
+ *                         closed. If this is not a concern, for example if
+ *                         your platform's stdio doesn't have any buffering,
+ *                         you can set mbedtls_setbuf to a function that
+ *                         does nothing.
+ *
+ *                         The library always calls this function with
+ *                         `buf` equal to `NULL`.
+ */
+extern void (*mbedtls_setbuf)( FILE *stream, char *buf );
+
+/**
+ * \brief                  Dynamically configure the function that is called
+ *                         when the mbedtls_setbuf() function is called by the
+ *                         library.
+ *
+ * \param   setbuf_func   The \c setbuf function implementation
+ *
+ * \return                 \c 0
+ */
+int mbedtls_platform_set_setbuf( void (*setbuf_func)(
+                                     FILE *stream, char *buf ) );
+#elif defined(MBEDTLS_PLATFORM_SETBUF_MACRO)
+/**
+ * \brief                  Macro defining the function for the library to
+ *                         call for `setbuf` functionality (changing the
+ *                         internal buffering on stdio calls).
+ *
+ * \note                   See extra comments on the mbedtls_setbuf() function
+ *                         pointer above.
+ *
+ * \return                 \c 0 on success, negative on error.
+ */
+#define mbedtls_setbuf    MBEDTLS_PLATFORM_SETBUF_MACRO
+#else
+#define mbedtls_setbuf    setbuf
+#endif /* MBEDTLS_PLATFORM_SETBUF_ALT / MBEDTLS_PLATFORM_SETBUF_MACRO */
+
 /*
  * The function pointers for exit
  */
diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index 23ea07b23..43f490e83 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -607,6 +607,9 @@ int mbedtls_ctr_drbg_write_seed_file( mbedtls_ctr_drbg_context *ctx,
     if( ( f = fopen( path, "wb" ) ) == NULL )
         return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     if( ( ret = mbedtls_ctr_drbg_random( ctx, buf,
                                          MBEDTLS_CTR_DRBG_MAX_INPUT ) ) != 0 )
         goto exit;
@@ -640,6 +643,9 @@ int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx,
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     n = fread( buf, 1, sizeof( buf ), f );
     if( fread( &c, 1, 1, f ) != 0 )
     {
diff --git a/library/dhm.c b/library/dhm.c
index 2ce0ed4fd..1e95bdab0 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -620,6 +620,7 @@ static int load_file( const char *path, unsigned char **buf, size_t *n )
 
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_DHM_FILE_IO_ERROR );
+    /* The data loaded here is public, so don't bother disabling buffering. */
 
     fseek( f, 0, SEEK_END );
     if( ( size = ftell( f ) ) == -1 )
diff --git a/library/entropy.c b/library/entropy.c
index 9e31f8491..08c5bd7d1 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -457,6 +457,9 @@ int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *p
         goto exit;
     }
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) != MBEDTLS_ENTROPY_BLOCK_SIZE )
     {
         ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
@@ -484,6 +487,9 @@ int mbedtls_entropy_update_seed_file( mbedtls_entropy_context *ctx, const char *
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     fseek( f, 0, SEEK_END );
     n = (size_t) ftell( f );
     fseek( f, 0, SEEK_SET );
diff --git a/library/entropy_poll.c b/library/entropy_poll.c
index 058c307df..2ae57fdc0 100644
--- a/library/entropy_poll.c
+++ b/library/entropy_poll.c
@@ -35,7 +35,7 @@
 #if defined(MBEDTLS_TIMING_C)
 #include "mbedtls/timing.h"
 #endif
-#if defined(MBEDTLS_ENTROPY_NV_SEED)
+#if defined(MBEDTLS_ENTROPY_NV_SEED) || !defined(HAVE_SYSCTL_ARND)
 #include "mbedtls/platform.h"
 #endif
 
@@ -195,6 +195,9 @@ int mbedtls_platform_entropy_poll( void *data,
     if( file == NULL )
         return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( file, NULL );
+
     read_len = fread( output, 1, len, file );
     if( read_len != len )
     {
diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
index ab353bfd5..8b13a860f 100644
--- a/library/hmac_drbg.c
+++ b/library/hmac_drbg.c
@@ -436,6 +436,9 @@ int mbedtls_hmac_drbg_write_seed_file( mbedtls_hmac_drbg_context *ctx, const cha
     if( ( f = fopen( path, "wb" ) ) == NULL )
         return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     if( ( ret = mbedtls_hmac_drbg_random( ctx, buf, sizeof( buf ) ) ) != 0 )
         goto exit;
 
@@ -465,6 +468,9 @@ int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const ch
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     n = fread( buf, 1, sizeof( buf ), f );
     if( fread( &c, 1, 1, f ) != 0 )
     {
diff --git a/library/md.c b/library/md.c
index f2c1a90f8..a387da50a 100644
--- a/library/md.c
+++ b/library/md.c
@@ -605,6 +605,9 @@ int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path, unsigne
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_MD_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     mbedtls_md_init( &ctx );
 
     if( ( ret = mbedtls_md_setup( &ctx, md_info, 0 ) ) != 0 )
diff --git a/library/pkparse.c b/library/pkparse.c
index 68727ec7e..722abd741 100644
--- a/library/pkparse.c
+++ b/library/pkparse.c
@@ -82,6 +82,9 @@ int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n )
     if( ( f = fopen( path, "rb" ) ) == NULL )
         return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( f, NULL );
+
     fseek( f, 0, SEEK_END );
     if( ( size = ftell( f ) ) == -1 )
     {
diff --git a/library/platform.c b/library/platform.c
index e742fde7c..6151e6c49 100644
--- a/library/platform.c
+++ b/library/platform.c
@@ -226,6 +226,28 @@ int mbedtls_platform_set_fprintf( int (*fprintf_func)( FILE *, const char *, ...
 }
 #endif /* MBEDTLS_PLATFORM_FPRINTF_ALT */
 
+#if defined(MBEDTLS_PLATFORM_SETBUF_ALT)
+#if !defined(MBEDTLS_PLATFORM_STD_SETBUF)
+/*
+ * Make dummy function to prevent NULL pointer dereferences
+ */
+static void platform_setbuf_uninit( FILE *stream, char *buf )
+{
+   ((void) stream);
+   ((void) buf);
+}
+
+#define MBEDTLS_PLATFORM_STD_SETBUF   platform_setbuf_uninit
+#endif /* !MBEDTLS_PLATFORM_STD_SETBUF */
+void (*mbedtls_setbuf)( FILE *stream, char *buf ) = MBEDTLS_PLATFORM_STD_SETBUF;
+
+int mbedtls_platform_set_setbuf( void (*setbuf_func)( FILE *stream, char *buf ) )
+{
+   mbedtls_setbuf = setbuf_func;
+   return( 0 );
+}
+#endif /* MBEDTLS_PLATFORM_SETBUF_ALT */
+
 #if defined(MBEDTLS_PLATFORM_EXIT_ALT)
 #if !defined(MBEDTLS_PLATFORM_STD_EXIT)
 /*
@@ -288,6 +310,9 @@ int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
     if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
         return( -1 );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( file, NULL );
+
     if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
     {
         fclose( file );
@@ -307,6 +332,9 @@ int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
     if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
         return -1;
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( file, NULL );
+
     if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
     {
         fclose( file );
diff --git a/library/psa_its_file.c b/library/psa_its_file.c
index f05872095..b7c2e6b04 100644
--- a/library/psa_its_file.c
+++ b/library/psa_its_file.c
@@ -102,6 +102,9 @@ static psa_status_t psa_its_read_file( psa_storage_uid_t uid,
     if( *p_stream == NULL )
         return( PSA_ERROR_DOES_NOT_EXIST );
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( *p_stream, NULL );
+
     n = fread( &header, 1, sizeof( header ), *p_stream );
     if( n != sizeof( header ) )
         return( PSA_ERROR_DATA_CORRUPT );
@@ -201,9 +204,13 @@ psa_status_t psa_its_set( psa_storage_uid_t uid,
 
     psa_its_fill_filename( uid, filename );
     stream = fopen( PSA_ITS_STORAGE_TEMP, "wb" );
+
     if( stream == NULL )
         goto exit;
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( stream, NULL );
+
     status = PSA_ERROR_INSUFFICIENT_STORAGE;
     n = fwrite( &header, 1, sizeof( header ), stream );
     if( n != sizeof( header ) )
diff --git a/programs/aes/crypt_and_hash.c b/programs/aes/crypt_and_hash.c
index 728854875..136e25ba4 100644
--- a/programs/aes/crypt_and_hash.c
+++ b/programs/aes/crypt_and_hash.c
@@ -166,6 +166,10 @@ int main( int argc, char *argv[] )
         goto exit;
     }
 
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( fin, NULL );
+    mbedtls_setbuf( fout, NULL );
+
     /*
      * Read the Cipher and MD from the command line
      */
diff --git a/programs/psa/key_ladder_demo.c b/programs/psa/key_ladder_demo.c
index cad875e01..13037190d 100644
--- a/programs/psa/key_ladder_demo.c
+++ b/programs/psa/key_ladder_demo.c
@@ -56,6 +56,7 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "mbedtls/platform.h" // for mbedtls_setbuf
 #include "mbedtls/platform_util.h" // for mbedtls_platform_zeroize
 
 #include <psa/crypto.h>
@@ -177,6 +178,8 @@ static psa_status_t save_key( psa_key_id_t key,
                                key_data, sizeof( key_data ),
                                &key_size ) );
     SYS_CHECK( ( key_file = fopen( output_file_name, "wb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( key_file, NULL );
     SYS_CHECK( fwrite( key_data, 1, key_size, key_file ) == key_size );
     SYS_CHECK( fclose( key_file ) == 0 );
     key_file = NULL;
@@ -231,6 +234,8 @@ static psa_status_t import_key_from_file( psa_key_usage_t usage,
     unsigned char extra_byte;
 
     SYS_CHECK( ( key_file = fopen( key_file_name, "rb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( key_file, NULL );
     SYS_CHECK( ( key_size = fread( key_data, 1, sizeof( key_data ),
                                    key_file ) ) != 0 );
     if( fread( &extra_byte, 1, 1, key_file ) != 0 )
@@ -372,6 +377,8 @@ static psa_status_t wrap_data( const char *input_file_name,
 
     /* Find the size of the data to wrap. */
     SYS_CHECK( ( input_file = fopen( input_file_name, "rb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( input_file, NULL );
     SYS_CHECK( fseek( input_file, 0, SEEK_END ) == 0 );
     SYS_CHECK( ( input_position = ftell( input_file ) ) != -1 );
 #if LONG_MAX > SIZE_MAX
@@ -418,6 +425,8 @@ static psa_status_t wrap_data( const char *input_file_name,
 
     /* Write the output. */
     SYS_CHECK( ( output_file = fopen( output_file_name, "wb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( output_file, NULL );
     SYS_CHECK( fwrite( &header, 1, sizeof( header ),
                        output_file ) == sizeof( header ) );
     SYS_CHECK( fwrite( buffer, 1, ciphertext_size,
@@ -453,6 +462,8 @@ static psa_status_t unwrap_data( const char *input_file_name,
 
     /* Load and validate the header. */
     SYS_CHECK( ( input_file = fopen( input_file_name, "rb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( input_file, NULL );
     SYS_CHECK( fread( &header, 1, sizeof( header ),
                       input_file ) == sizeof( header ) );
     if( memcmp( &header.magic, WRAPPED_DATA_MAGIC,
@@ -509,6 +520,8 @@ static psa_status_t unwrap_data( const char *input_file_name,
 
     /* Write the output. */
     SYS_CHECK( ( output_file = fopen( output_file_name, "wb" ) ) != NULL );
+    /* Ensure no stdio buffering of secrets, as such buffers cannot be wiped. */
+    mbedtls_setbuf( output_file, NULL );
     SYS_CHECK( fwrite( buffer, 1, plaintext_size,
                        output_file ) == plaintext_size );
     SYS_CHECK( fclose( output_file ) == 0 );
diff --git a/programs/ssl/ssl_test_common_source.c b/programs/ssl/ssl_test_common_source.c
index 511ede9cb..24e1f3eee 100644
--- a/programs/ssl/ssl_test_common_source.c
+++ b/programs/ssl/ssl_test_common_source.c
@@ -101,6 +101,10 @@ void nss_keylog_export( void *p_expkey,
             goto exit;
         }
 
+        /* Ensure no stdio buffering of secrets, as such buffers cannot be
+         * wiped. */
+        mbedtls_setbuf( f, NULL );
+
         if( fwrite( nss_keylog_line, 1, len, f ) != len )
         {
             fclose( f );
diff --git a/programs/ssl/ssl_test_lib.h b/programs/ssl/ssl_test_lib.h
index 03349babb..c368f573a 100644
--- a/programs/ssl/ssl_test_lib.h
+++ b/programs/ssl/ssl_test_lib.h
@@ -34,6 +34,7 @@
 #define mbedtls_printf     printf
 #define mbedtls_fprintf    fprintf
 #define mbedtls_snprintf   snprintf
+#define mbedtls_setbuf     setbuf
 #define mbedtls_exit            exit
 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 27c211fbf..458fe8f5b 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2253,6 +2253,7 @@ component_test_no_platform () {
     scripts/config.py unset MBEDTLS_PLATFORM_SNPRINTF_ALT
     scripts/config.py unset MBEDTLS_PLATFORM_TIME_ALT
     scripts/config.py unset MBEDTLS_PLATFORM_EXIT_ALT
+    scripts/config.py unset MBEDTLS_PLATFORM_SETBUF_ALT
     scripts/config.py unset MBEDTLS_PLATFORM_NV_SEED_ALT
     scripts/config.py unset MBEDTLS_ENTROPY_NV_SEED
     scripts/config.py unset MBEDTLS_FS_IO