Fix compilation

Author: timothyschoen

CMakeLists.txt

@@ -48,7 +48,7 @@ if(APPLE)
   set(CMAKE_XCODE_BUILD_SYSTEM "12" CACHE STRING "" FORCE)
   if("${CMAKE_SYSTEM_NAME}" MATCHES "iOS")
     set(CMAKE_OSX_DEPLOYMENT_TARGET "12.0" CACHE STRING "Minimum iOS deployment version")
-  elif(MACOS_LEGACY)
+  elseif(MACOS_LEGACY)
     set(CMAKE_OSX_DEPLOYMENT_TARGET "10.11" CACHE STRING "Minimum macOS deployment version")
     set(CMAKE_OSX_ARCHITECTURES "x86_64;" CACHE STRING "" FORCE)
   else()