diff --git a/cpp/BoostParts/CMakeLists.txt b/cpp/BoostParts/CMakeLists.txt
index a22ec09d..216bd52f 100644
--- a/cpp/BoostParts/CMakeLists.txt
+++ b/cpp/BoostParts/CMakeLists.txt
@@ -86,6 +86,12 @@ endif()
 # TODO: remove this when it's fixed upstream (probably boost 1.53).
 add_definitions( -DBOOST_THREAD_DONT_USE_CHRONO )
 
+if( MSVC )
+  # BOOST_PYTHON_SOURCE makes boost use the correct __declspec and
+  # BOOST_ALL_NO_LIB turns off MSVC library autolinking
+  add_definitions( -DBOOST_PYTHON_SOURCE -DBOOST_ALL_NO_LIB )
+endif()
+
 #############################################################################
 
 include_directories(
diff --git a/plugin/youcompleteme.vim b/plugin/youcompleteme.vim
index 43acc035..959fafb7 100644
--- a/plugin/youcompleteme.vim
+++ b/plugin/youcompleteme.vim
@@ -35,7 +35,7 @@ function! s:HasYcmCore()
   let path_prefix = s:script_folder_path . '/../python/'
   if filereadable(path_prefix . 'ycm_core.so')
     return 1
-  elseif filereadable(path_prefix . 'ycm_core.dll')
+  elseif filereadable(path_prefix . 'ycm_core.pyd')
     return 1
   endif
   return 0