diff --git a/src/rose/rose_build_bytecode.cpp b/src/rose/rose_build_bytecode.cpp
index 197ceb4a..a50ebb8e 100644
--- a/src/rose/rose_build_bytecode.cpp
+++ b/src/rose/rose_build_bytecode.cpp
@@ -5409,6 +5409,15 @@ aligned_unique_ptr<RoseEngine> RoseBuildImpl::buildFinalEngine(u32 minWidth) {
     allocateFinalLiteralId(*this, bc);
     final_to_frag_map = groupByFragment(*this, bc);
 
+    // Write the fragment IDs into the literal_info structures.
+    for (auto &info : literal_info) {
+        if (info.final_id == MO_INVALID_IDX) {
+            continue;
+        }
+        assert(contains(final_to_frag_map, info.final_id));
+        info.fragment_id = final_to_frag_map.at(info.final_id).fragment_id;
+    }
+
     auto anchored_dfas = buildAnchoredDfas(*this);
 
     bc.floatingMinLiteralMatchOffset =
diff --git a/src/rose/rose_build_impl.h b/src/rose/rose_build_impl.h
index addd703c..bf588553 100644
--- a/src/rose/rose_build_impl.h
+++ b/src/rose/rose_build_impl.h
@@ -264,7 +264,8 @@ struct rose_literal_info {
     ue2::flat_set<RoseVertex> vertices;
     rose_group group_mask = 0;
     u32 undelayed_id = MO_INVALID_IDX;
-    u32 final_id = MO_INVALID_IDX; /* id reported by fdr */
+    u32 final_id = MO_INVALID_IDX; // TODO: remove
+    u32 fragment_id = MO_INVALID_IDX; //!< ID corresponding to literal prog.
     bool squash_group = false;
     bool requires_benefits = false;
 };