diff --git a/PWGUD/TableProducer/UPCCandidateProducer.cxx b/PWGUD/TableProducer/UPCCandidateProducer.cxx
index 80642313a7c..1dac593260f 100644
--- a/PWGUD/TableProducer/UPCCandidateProducer.cxx
+++ b/PWGUD/TableProducer/UPCCandidateProducer.cxx
@@ -51,11 +51,11 @@
 #include <limits>
 #include <map>
 #include <numeric>
+#include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>
 #include <vector>
-#include <string>
 
 using namespace o2::framework;
 using namespace o2::framework::expressions;