diff --git a/tool/speed.cc b/tool/speed.cc
index 28a07a1865..7c17d89c45 100644
--- a/tool/speed.cc
+++ b/tool/speed.cc
@@ -1261,7 +1261,7 @@ const size_t SCRATCH_SIZE = 16384;
 
 using RandomFunction = std::function<void(uint8_t *, size_t)>;
 static bool SpeedRandomChunk(RandomFunction function, std::string name, size_t chunk_len) {
-  bssl::UniquePtr<uint8_t> scratch((uint8_t*)OPENSSL_malloc(SCRATCH_SIZE));
+  std::unique_ptr<uint8_t[]> scratch(new uint8_t[SCRATCH_SIZE]);
 
   if (chunk_len > SCRATCH_SIZE) {
     return false;