diff --git a/include/ggml/ggml-backend.h b/include/ggml/ggml-backend.h
index 744b6a774..fbdba0dae 100644
--- a/include/ggml/ggml-backend.h
+++ b/include/ggml/ggml-backend.h
@@ -7,10 +7,7 @@
 extern "C" {
 #endif
 
-    typedef struct ggml_backend_buffer_type * ggml_backend_buffer_type_t;
-    typedef struct ggml_backend_buffer * ggml_backend_buffer_t;
     typedef struct ggml_backend_event * ggml_backend_event_t;
-    typedef struct ggml_backend * ggml_backend_t;
     typedef void * ggml_backend_graph_plan_t;
 
     //