diff --git a/indra/cmake/GLEXT.cmake b/indra/cmake/GLEXT.cmake
index 415b13033c6313cd59835acd8e008b0de990ef79..2a08c8fbaeb5890f50ca288d29ee6bd68852ab72 100644
--- a/indra/cmake/GLEXT.cmake
+++ b/indra/cmake/GLEXT.cmake
@@ -2,7 +2,9 @@
 include(Prebuilt)
 
 if (NOT USESYSTEMLIBS)
-  use_prebuilt_binary(glext)
+  if (WINDOWS OR LINUX)
+    use_prebuilt_binary(glext)
+  endif (WINDOWS OR LINUX)
   use_prebuilt_binary(glh-linear)
   set(GLEXT_INCLUDE_DIR ${LIBS_PREBUILT_DIR}/include)
 endif (NOT USESYSTEMLIBS)