diff --git a/CMakeLists.txt b/CMakeLists.txt
index 67643883..cfccb656 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -391,6 +391,11 @@ endif()
 if(ENABLE_QT_GUI)
     target_compile_definitions(Alber PUBLIC "PANDA3DS_FRONTEND_QT=1")
     target_link_libraries(Alber PRIVATE Qt6::Widgets)
+
+    if(LINUX OR FREEBSD)
+        find_package(X11 REQUIRED)
+        target_link_libraries(Alber PRIVATE ${X11_LIBRARIES})
+    endif()
 else()
     target_compile_definitions(Alber PUBLIC "PANDA3DS_FRONTEND_SDL=1")
 endif()