diff --git a/src/rose/rose_build_merge.cpp b/src/rose/rose_build_merge.cpp
index cddbb760..6dad3ecd 100644
--- a/src/rose/rose_build_merge.cpp
+++ b/src/rose/rose_build_merge.cpp
@@ -1599,7 +1599,8 @@ void dedupeLeftfixesVariableLag(RoseBuildImpl &build) {
                 continue;
             }
         }
-        engine_groups[DedupeLeftKey(build, std::move(preds), left)].emplace_back(left);
+        auto preds_copy = preds;
+        engine_groups[DedupeLeftKey(build, std::move(preds_copy), left)].emplace_back(left);
     }
 
     /* We don't bother chunking as we expect deduping to be successful if the