--- doomsday-2.0.0/doomsday/sdk/libgui/CMakeLists.txt.orig	2017-04-01 02:37:17.000000000 +0200
+++ doomsday-2.0.0/doomsday/sdk/libgui/CMakeLists.txt	2017-04-17 22:28:36.107038519 +0200
@@ -123,7 +123,7 @@
 
 if (DENG_X11)
     target_include_directories (libgui PRIVATE ${X11_INCLUDE_DIR})
-    target_link_libraries (libgui PRIVATE ${X11_LIBRARIES})
+    target_link_libraries (libgui PRIVATE ${X11_LIBRARIES} GL)
     deng_target_link_qt (libgui PRIVATE X11Extras)
     if (DENG_ENABLE_DISPLAYMODE)
         if (NOT X11_Xrandr_FOUND)
@@ -148,6 +148,7 @@
 # If Assimp is part of the build, ensure that it gets compiled before libgui.
 if (TARGET assimp)
     add_dependencies (libgui assimp)
+    target_link_libraries (libgui PRIVATE z)
     if (MSVC)
         target_link_libraries (libgui PRIVATE zlibstatic)   # from assimp project
     endif ()