diff --git a/panda/src/gobj/preparedGraphicsObjects.cxx b/panda/src/gobj/preparedGraphicsObjects.cxx
index e3ab0e8d83..099b40c899 100644
--- a/panda/src/gobj/preparedGraphicsObjects.cxx
+++ b/panda/src/gobj/preparedGraphicsObjects.cxx
@@ -1371,6 +1371,8 @@ release_all_shader_buffers() {
        ++bci) {
 
     BufferContext *bc = (BufferContext *)(*bci);
+    ((ShaderBuffer *)bc->_object)->clear_prepared(this);
+    bc->_object = nullptr;
     _released_shader_buffers.insert(bc);
   }