diff --git a/library/cipher.c b/library/cipher.c
index 53ed9b3..20af256 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -286,7 +286,7 @@
 
     if ( actual_iv_size != 0 )
     {
-        memcpy( ctx->iv, iv, actual_iv_size );
+        mbedtls_platform_memcpy( ctx->iv, iv, actual_iv_size );
         ctx->iv_size = actual_iv_size;
     }
 
@@ -422,7 +422,7 @@
              ( ctx->operation == MBEDTLS_ENCRYPT &&
                 ilen < block_size - ctx->unprocessed_len ) )
         {
-            memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
+            mbedtls_platform_memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
                     ilen );
 
             ctx->unprocessed_len += ilen;
@@ -436,7 +436,7 @@
         {
             copy_len = block_size - ctx->unprocessed_len;
 
-            memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
+            mbedtls_platform_memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ), input,
                     copy_len );
 
             if( 0 != ( ret = ctx->cipher_info->base->cbc_func( ctx->cipher_ctx,
@@ -476,7 +476,7 @@
                 copy_len = block_size;
             }
 
-            memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
+            mbedtls_platform_memcpy( ctx->unprocessed_data, &( input[ilen - copy_len] ),
                     copy_len );
 
             ctx->unprocessed_len += copy_len;