diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7064582d..9bbbfc47 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -183,7 +183,7 @@ include (CheckCXXSymbolExists)
 
 check_include_files (ifaddrs.h ZMQ_HAVE_IFADDRS)
 check_include_files (windows.h ZMQ_HAVE_WINDOWS)
-if( ${CMAKE_SYSTEM_NAME} STREQUAL "WindowsStore" AND ${CMAKE_SYSTEM_VERSION} STREQUAL "10.0")
+if(CMAKE_SYSTEM_NAME STREQUAL "WindowsStore" AND CMAKE_SYSTEM_VERSION STREQUAL "10.0")
   SET(ZMQ_HAVE_WINDOWS_UWP ON)
   ADD_DEFINITIONS(-D_WIN32_WINNT=_WIN32_WINNT_WIN10)
 endif()