diff --git a/library/cipher.c b/library/cipher.c
index 5821716..47dfe24 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -156,7 +156,7 @@
 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx )
 {
     CIPHER_VALIDATE( ctx != NULL );
-    memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
+    mbedtls_platform_memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
 }
 
 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx )
@@ -185,7 +185,7 @@
     if( cipher_info == NULL )
         return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
-    memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
+    mbedtls_platform_memset( ctx, 0, sizeof( mbedtls_cipher_context_t ) );
 
     if( NULL == ( ctx->cipher_ctx = cipher_info->base->ctx_alloc_func() ) )
         return( MBEDTLS_ERR_CIPHER_ALLOC_FAILED );