diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4e1a35b1d..4861dd3ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,6 +16,7 @@ INCLUDE_DIRECTORIES (${CMAKE_BINARY_DIR}/include)
 
 IF(CMAKE_COMPILER_IS_GNUCC)
     SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=c99 -DHAVE__BOOL")
+ELSEIF(MSVC)
 ELSE(CMAKE_COMPILER_IS_GNUCC)
     MESSAGE(STATUS "Unknown compiler ${CMAKE_C_COMPILER_ID}")
 ENDIF(CMAKE_COMPILER_IS_GNUCC)