diff --git a/Device/Histo/SimulationResult.cpp b/Device/Histo/SimulationResult.cpp
index 8cdfd5474489797866afa22d3390522cf2f88fb9..89a2740fc32537f19c46d736cd40e2ba9f8ea113 100644
--- a/Device/Histo/SimulationResult.cpp
+++ b/Device/Histo/SimulationResult.cpp
@@ -44,12 +44,12 @@ SimulationResult& SimulationResult::operator=(SimulationResult&& other) noexcept
 
 size_t SimulationResult::rank() const
 {
-    return m_data->rank();
+    return m_coordsys ? m_coordsys->rank() : 0;
 }
 
 size_t SimulationResult::size() const
 {
-    return m_data ? m_data->size() : 0;
+    return m_coordsys ? m_coordsys->size() : 0;
 }
 
 bool SimulationResult::empty() const