diff --git a/src/EquationTags.hh b/src/EquationTags.hh
index 873b349ec66c1d8a3e55a17830183e26f9f9edb9..1a2292c7ebf934c49847ccec21c10c2dcdd52d18 100644
--- a/src/EquationTags.hh
+++ b/src/EquationTags.hh
@@ -45,7 +45,7 @@ public:
   inline void add(int eqn, map<string, string> tags)
   {
     if (eqn_tags.contains(eqn))
-      eqn_tags[eqn].insert(tags.begin(), tags.end());
+      eqn_tags[eqn].insert(move_iterator{tags.begin()}, move_iterator{tags.end()});
     else
       eqn_tags[eqn] = move(tags);
   }