diff --git a/indra/cmake/OpenGL.cmake b/indra/cmake/OpenGL.cmake
index 2259c99293..9f3e4ee63f 100644
--- a/indra/cmake/OpenGL.cmake
+++ b/indra/cmake/OpenGL.cmake
@@ -3,6 +3,10 @@
 include(Variables)
 include(Prebuilt)
 
+# <FS:TS> Shut cmake up about OpenGL library preference. This can
+# be either LEGACY or GLVND.
+SET(OpenGL_GL_PREFERENCE LEGACY)
+
 if (BUILD_HEADLESS)
   SET(OPENGL_glu_LIBRARY GLU)
   SET(OPENGL_HEADLESS_LIBRARIES OSMesa16 dl GLU)