diff --git a/build/cmake/DefinePlatformSpecifc.cmake b/build/cmake/DefinePlatformSpecifc.cmake
index 626f5e5..cbd5ca8 100644
--- a/build/cmake/DefinePlatformSpecifc.cmake
+++ b/build/cmake/DefinePlatformSpecifc.cmake
@@ -90,9 +90,7 @@
 add_definitions("-D__STDC_LIMIT_MACROS")
 
 # WITH_*THREADS selects which threading library to use
-if(WITH_BOOSTTHREADS)
-  add_definitions("-DUSE_BOOST_THREAD=1")
-elseif(WITH_STDTHREADS)
+if(WITH_STDTHREADS)
   add_definitions("-DUSE_STD_THREAD=1")
 endif()