diff --git a/cpp/BoostParts/CMakeLists.txt b/cpp/BoostParts/CMakeLists.txt
index bb86c7d8..fe65719d 100644
--- a/cpp/BoostParts/CMakeLists.txt
+++ b/cpp/BoostParts/CMakeLists.txt
@@ -86,7 +86,7 @@ endif()
 # TODO: remove this when it's fixed upstream (probably boost 1.53).
 add_definitions( -DBOOST_THREAD_DONT_USE_CHRONO )
 
-if( MSVC )
+if( MSVC OR CYGWIN )
   # 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 )
diff --git a/cpp/ycm/CMakeLists.txt b/cpp/ycm/CMakeLists.txt
index 50a9e8c1..8b00a259 100644
--- a/cpp/ycm/CMakeLists.txt
+++ b/cpp/ycm/CMakeLists.txt
@@ -223,6 +223,11 @@ endif()
 # TODO: remove this when it's fixed upstream (probably boost 1.53).
 add_definitions( -DBOOST_THREAD_DONT_USE_CHRONO )
 
+if( MSVC OR CYGWIN )
+  # 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()
 #############################################################################
 
 add_library( ${PROJECT_NAME} SHARED
@@ -274,7 +279,7 @@ set_target_properties( ${PROJECT_NAME} PROPERTIES PREFIX "")
 # Even on macs, we want a .so extension instead of a .dylib which is what cmake
 # would give us by default. Python won't recognize a .dylib as a module, but it
 # will recognize a .so
-if ( NOT WIN32 )
+if ( NOT WIN32 AND NOT CYGWIN )
   set_target_properties( ${PROJECT_NAME} PROPERTIES SUFFIX ".so")
 endif()
 
diff --git a/plugin/youcompleteme.vim b/plugin/youcompleteme.vim
index 225f6f7f..fd4c5bfa 100644
--- a/plugin/youcompleteme.vim
+++ b/plugin/youcompleteme.vim
@@ -39,6 +39,8 @@ 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')
+    return 1
   elseif filereadable(path_prefix . 'ycm_core.pyd')
     return 1
   endif