diff --git a/include/openPMD/Mesh.hpp b/include/openPMD/Mesh.hpp
index dd830a5613..62d574b67a 100644
--- a/include/openPMD/Mesh.hpp
+++ b/include/openPMD/Mesh.hpp
@@ -260,7 +260,7 @@ class Mesh : public BaseRecord<MeshRecordComponent>
      * @return Reference to modified mesh.
      */
     Mesh &setGridUnitDimension(
-        std::vector<std::map<UnitDimension, double>> const & gridUnitDimension);
+        std::vector<std::map<UnitDimension, double>> const &gridUnitDimension);
 
     /**
      * @brief Return the physical dimensions of the mesh axes.