diff --git a/include/mbedtls/base64.h b/include/mbedtls/base64.h
index 07ae3bf..f7e51b2 100644
--- a/include/mbedtls/base64.h
+++ b/include/mbedtls/base64.h
@@ -30,6 +30,7 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+#include "mbedtls/platform_util.h"
 #include <stddef.h>
 
 #define MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL               -0x002A  /**< Output buffer too small. */
@@ -58,6 +59,7 @@
  * \note           Call this function with dlen = 0 to obtain the
  *                 required buffer size in *olen
  */
+MBEDTLS_DEPRECATED
 int mbedtls_base64_encode( unsigned char *dst, size_t dlen, size_t *olen,
                    const unsigned char *src, size_t slen );
 
@@ -78,6 +80,7 @@
  * \note           Call this function with *dst = NULL or dlen = 0 to obtain
  *                 the required buffer size in *olen
  */
+MBEDTLS_DEPRECATED
 int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
                    const unsigned char *src, size_t slen );
 
@@ -87,6 +90,7 @@
  *
  * \return         0 if successful, or 1 if the test failed
  */
+MBEDTLS_DEPRECATED
 int mbedtls_base64_self_test( int verbose );
 
 #endif /* MBEDTLS_SELF_TEST */