diff --git a/library/pkwrite.c b/library/pkwrite.c
index 8b99340..17343c2 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -59,11 +59,6 @@
 #define mbedtls_free       free
 #endif
 
-/* Parameter validation macros based on platform_util.h */
-#define PK_VALIDATE_RET( cond )    \
-    MBEDTLS_INTERNAL_VALIDATE_RET( cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA )
-#define PK_VALIDATE( cond )        \
-    MBEDTLS_INTERNAL_VALIDATE( cond )
 
 #if defined(MBEDTLS_RSA_C)
 /*
@@ -182,10 +177,6 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t len = 0;
 
-    PK_VALIDATE_RET( p != NULL );
-    PK_VALIDATE_RET( *p != NULL );
-    PK_VALIDATE_RET( start != NULL );
-    PK_VALIDATE_RET( key != NULL );
 
 #if defined(MBEDTLS_RSA_C)
     if( mbedtls_pk_get_type( key ) == MBEDTLS_PK_RSA )
@@ -233,10 +224,8 @@
     mbedtls_pk_type_t pk_type;
     const char *oid;
 
-    PK_VALIDATE_RET( key != NULL );
     if( size == 0 )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
-    PK_VALIDATE_RET( buf != NULL );
 
     c = buf + size;
 
@@ -333,10 +322,8 @@
     unsigned char *c;
     size_t len = 0;
 
-    PK_VALIDATE_RET( key != NULL );
     if( size == 0 )
         return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
-    PK_VALIDATE_RET( buf != NULL );
 
     c = buf + size;
 
@@ -500,8 +487,6 @@
     unsigned char output_buf[PUB_DER_MAX_BYTES];
     size_t olen = 0;
 
-    PK_VALIDATE_RET( key != NULL );
-    PK_VALIDATE_RET( buf != NULL || size == 0 );
 
     if( ( ret = mbedtls_pk_write_pubkey_der( key, output_buf,
                                      sizeof(output_buf) ) ) < 0 )
@@ -526,8 +511,6 @@
     const char *begin, *end;
     size_t olen = 0;
 
-    PK_VALIDATE_RET( key != NULL );
-    PK_VALIDATE_RET( buf != NULL || size == 0 );
 
     if( ( ret = mbedtls_pk_write_key_der( key, output_buf, sizeof(output_buf) ) ) < 0 )
         return( ret );