diff --git a/library/ctr_drbg.c b/library/ctr_drbg.c
index dd8aad6..069303f 100644
--- a/library/ctr_drbg.c
+++ b/library/ctr_drbg.c
@@ -649,7 +649,7 @@
                                        size_t len )
 {
     const unsigned char *p = data;
-    mbedtls_platform_memcpy( buf, p + test_offset, len );
+    memcpy( buf, p + test_offset, len );
     test_offset += len;
     return( 0 );
 }