diff --git a/CMakeLists.txt b/CMakeLists.txt
index f273543..c698cdc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -158,7 +158,7 @@ else(WIN32)
   else(COMPILER_SUPPORTS_ftpz)
     message(STATUS "The compiler ${CMAKE_CXX_COMPILER} doesn't support -fdenormal-fp-math=positive-zero.")
   endif(COMPILER_SUPPORTS_ftpz)
-  
+
   CHECK_CXX_COMPILER_FLAG("-ftree-vectorize -ftree-vectorizer-verbose=2" COMPILER_SUPPORTS_ftree_vectorize)
   if(COMPILER_SUPPORTS_ftree_vectorize)
     set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ftree-vectorize -ftree-vectorizer-verbose=2")
@@ -334,7 +334,7 @@ endif(ENABLE_PYTHON)
 
 IF (BUILD_DOC)
 
-  FIND_PACKAGE(Doxygen Required)
+  FIND_PACKAGE(Doxygen REQUIRED)
 
   SET(DOXYGEN_INPUT Doxyfile)
   SET(DOXYGEN_OUTPUT Doxygen)