diff --git a/src/gallium/drivers/r300/r300_context.c b/src/gallium/drivers/r300/r300_context.c
index e36749a0065..93f1cd81655 100644
--- a/src/gallium/drivers/r300/r300_context.c
+++ b/src/gallium/drivers/r300/r300_context.c
@@ -47,6 +47,7 @@ static void r300_release_referenced_objects(struct r300_context *r300)
 
     /* Manually-created vertex buffers. */
     pipe_vertex_buffer_unreference(&r300->dummy_vb);
+    pipe_surface_reference(&r300->locked_zbuffer, NULL);
     radeon_bo_reference(r300->rws, &r300->vbo, NULL);
 
     r300->context.delete_depth_stencil_alpha_state(&r300->context,