diff --git a/ggml/src/ggml.c b/ggml/src/ggml.c
index cdc10a759..7c931afb9 100644
--- a/ggml/src/ggml.c
+++ b/ggml/src/ggml.c
@@ -7992,6 +7992,7 @@ void ggml_graph_dump_dot(const struct ggml_cgraph * gb, const struct ggml_cgraph
 ////////////////////////////////////////////////////////////////////////////////
 
 void ggml_set_input(struct ggml_tensor * tensor) {
+    GGML_ASSERT(tensor->op == GGML_OP_NONE);
     tensor->flags |= GGML_TENSOR_FLAG_INPUT;
 }