diff --git a/src/cpu/VirtualFluidsCore/Visitors/RefineAroundGbObjectHelper.cpp b/src/cpu/VirtualFluidsCore/Visitors/RefineAroundGbObjectHelper.cpp
index 2a377c834f28ae113dd595d0b417312bd94ffd97..a73965641237c804cd094f399e582336e6be8e04 100644
--- a/src/cpu/VirtualFluidsCore/Visitors/RefineAroundGbObjectHelper.cpp
+++ b/src/cpu/VirtualFluidsCore/Visitors/RefineAroundGbObjectHelper.cpp
@@ -40,7 +40,7 @@ void RefineAroundGbObjectHelper::refine()
     grid->accept(overlapVisitor);
 
     std::vector<int> dirs;
-    for (int i = DIR_P00; i <= DIR_0MP; i++) {
+    for (int i = (int)DIR_P00; i <= (int)DIR_0MP; i++) {
         dirs.push_back(i);
     }
     SetInterpolationDirsBlockVisitor interDirsVisitor(dirs);