diff --git a/lldb/tools/debugserver/source/CMakeLists.txt b/lldb/tools/debugserver/source/CMakeLists.txt
index 6c4fa026092b6..9a7e2eb9a1a0f 100644
--- a/lldb/tools/debugserver/source/CMakeLists.txt
+++ b/lldb/tools/debugserver/source/CMakeLists.txt
@@ -129,7 +129,7 @@ if(LLDB_USE_ENTITLEMENTS)
   endif()
 endif()
 
-if($ENV{SDKROOT} MATCHES ".Internal.sdk$")
+if(${CMAKE_OSX_SYSROOT} MATCHES ".Internal.sdk$")
   message(STATUS "LLDB debugserver energy support is enabled")
   add_definitions(-DLLDB_ENERGY)
   set(ENERGY_LIBRARY -lpmenergy -lpmsample)