diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0de08c9..6e0ac5b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -310,6 +310,7 @@ if (CMAKE_SYSTEM_NAME MATCHES "Linux")
     find_package(SDL2 REQUIRED)
     find_package(X11 REQUIRED)
 
+    add_compile_definitions("PLUME_SDL_VULKAN_ENABLED")
     add_compile_definitions("RT64_SDL_WINDOW_VULKAN")
 
     # Generate icon_bytes.c from the app icon PNG.
diff --git a/lib/rt64 b/lib/rt64
index af3855c..1a6db50 160000
--- a/lib/rt64
+++ b/lib/rt64
@@ -1 +1 @@
-Subproject commit af3855c8832bfeb5e73910e323ac8ff2452eea92
+Subproject commit 1a6db509e5fa0a680e6fda66444557169ce565d1