diff --git a/include/openPMD/auxiliary/StringManip.hpp b/include/openPMD/auxiliary/StringManip.hpp
index 66ad258554..54257d5cfb 100644
--- a/include/openPMD/auxiliary/StringManip.hpp
+++ b/include/openPMD/auxiliary/StringManip.hpp
@@ -261,7 +261,6 @@ namespace auxiliary
         auto end = v.end();
         std::stringstream res;
         res << '[' << *it++;
-        res.operator<<(*it);
         for (; it != end; ++it)
         {
             res << ", " << *it;