diff --git a/src/utils.cpp b/src/utils.cpp
index 5c5ccf0..3fc600b 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -21,8 +21,12 @@ inline ZYM::int2048 Any2Int(const std::any &value) {
       str = integer_part;
     }
     return std::move(ZYM::int2048(str));
-  } else
+  } else if (auto ptr = std::any_cast<NoneType>(&value))
+    return std::move(ZYM::int2048(0));
+  else {
+    std::cerr << value.type().name() << std::endl;
     throw FatalError("Any2Int2048: unknown type");
+  }
 }
 
 double Any2Float(const std::any &value) {