diff --git a/opm/core/simulator/initStateEquil.hpp b/opm/core/simulator/initStateEquil.hpp
index 7ed55cb56..b03d488a0 100644
--- a/opm/core/simulator/initStateEquil.hpp
+++ b/opm/core/simulator/initStateEquil.hpp
@@ -394,7 +394,7 @@ namespace Opm
                         const auto& cells = reg.cells(r);
                         if (cells.empty())
                         {
-                            OpmLog::warning("Equilibration region " + std::to_string(r) 
+                            OpmLog::warning("Equilibration region " + std::to_string(r + 1) 
                                             + " has no active cells");
                             continue;
                         }