diff --git a/src/libaevol/7/DnaFactory.cpp b/src/libaevol/7/DnaFactory.cpp
index dc1f5d2094cfa49560b0cceecb883b60ac037392..7d1e620f961e0def8e3ff4233859da82ed6e1454 100644
--- a/src/libaevol/7/DnaFactory.cpp
+++ b/src/libaevol/7/DnaFactory.cpp
@@ -94,7 +94,7 @@ void DnaFactory::init(Dna_7::size_type init_size, int pop_size) {
 
 Dna_7 *DnaFactory::get_dna(Dna_7::size_type request_size) {
   request_size++;  // Count the end \0
-  int req_block = Dna_7::nb_required_blocks(request_size);
+  auto req_block = Dna_7::nb_required_blocks(request_size);
   if (policy_ == DnaFactory_Policy::FIRST) {
     Dna_7 *pop    = nullptr;
     bool allocate = false;