diff '--color=auto' -ur onnx-1.18.0.orig/onnx/defs/schema.h onnx-1.18.0/onnx/defs/schema.h
--- onnx-1.18.0.orig/onnx/defs/schema.h	2025-05-08 19:33:57.000000000 +0200
+++ onnx-1.18.0/onnx/defs/schema.h	2025-08-13 19:58:25.393119867 +0200
@@ -980,7 +980,7 @@
   class OpSchemaRegisterOnce final {
    public:
     // Export to cpp custom register macro
-    explicit OpSchemaRegisterOnce(
+    OpSchemaRegisterOnce(
         OpSchema op_schema,
         int opset_version_to_load = 0,
         bool fail_duplicate_schema = true) {