diff --git a/ProcessLib/TES/TESLocalAssembler-impl.h b/ProcessLib/TES/TESLocalAssembler-impl.h
index bb3fc62238571c38f95de1457f5c2fb39341ae9d..1b5f1c178836a254d8108c7761b6aa6ed69d25b7 100644
--- a/ProcessLib/TES/TESLocalAssembler-impl.h
+++ b/ProcessLib/TES/TESLocalAssembler-impl.h
@@ -147,7 +147,7 @@ void TESLocalAssembler<ShapeFunction_, IntegrationMethod_, GlobalDim>::
 
     _d.preEachAssemble();
 
-    for (std::size_t ip(0); ip < n_integration_points; ip++)
+    for (unsigned ip = 0; ip < n_integration_points; ip++)
     {
         auto const& sm = _shape_matrices[ip];
         auto const& wp = integration_method.getWeightedPoint(ip);