diff --git a/fsgrid.hpp b/fsgrid.hpp
index cb81473..c0da3c3 100644
--- a/fsgrid.hpp
+++ b/fsgrid.hpp
@@ -1136,7 +1136,7 @@ template <typename T, int stencil> class FsGrid : public FsGridTools{
       uint numRequests;
 
       std::array<int, 27> neighbour; //!< Tasks of the 26 neighbours (plus ourselves)
-      std::vector<char> neighbour_index; //!< Lookup table from rank to index in the neighbour array
+      std::vector<int> neighbour_index; //!< Lookup table from rank to index in the neighbour array
 
       // We have, fundamentally, two different coordinate systems we're dealing with:
       // 1) Task grid in the MPI_Cartcomm