diff --git a/extern/re2/.gitignore b/extern/re2/.gitignore
index a671fe2cf0..ec01f39b64 100644
--- a/extern/re2/.gitignore
+++ b/extern/re2/.gitignore
@@ -3,3 +3,4 @@
 core
 obj/
 benchlog.*
+builds/
diff --git a/extern/re2/CMakeLists.txt b/extern/re2/CMakeLists.txt
index a1ef60d59b..f23bfa6012 100644
--- a/extern/re2/CMakeLists.txt
+++ b/extern/re2/CMakeLists.txt
@@ -45,6 +45,8 @@ if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
   # Without a byte order mark (BOM), Visual Studio assumes that the source
   # file is encoded using the current user code page, so we specify UTF-8.
   add_compile_options(/utf-8)
+  # allow multi-processor compilation
+  add_compile_options(/MP)
 endif()
 
 if(WIN32)