diff --git a/src/rose/rose_build_bytecode.cpp b/src/rose/rose_build_bytecode.cpp
index 68812b44..3356d214 100644
--- a/src/rose/rose_build_bytecode.cpp
+++ b/src/rose/rose_build_bytecode.cpp
@@ -186,10 +186,6 @@ struct build_context : boost::noncopyable {
      */
     size_t numStates = 0;
 
-    /** \brief Very simple cache from sparse iter to offset, used when building
-     * up iterators in early misc. */
-    map<vector<mmbit_sparse_iter>, u32> iterCache;
-
     /** \brief Simple cache of programs written to engine blob, used for
      * deduplication. */
     ue2::unordered_map<RoseProgram, u32, RoseProgramHash,
@@ -2178,24 +2174,6 @@ u32 RoseBuildImpl::calcHistoryRequired() const {
     return m ? m - 1 : 0;
 }
 
-// Adds a sparse iterator to the end of the iterator table, returning its
-// offset.
-static
-u32 addIteratorToTable(build_context &bc,
-                       const vector<mmbit_sparse_iter> &iter) {
-    if (contains(bc.iterCache, iter)) {
-        DEBUG_PRINTF("cache hit\n");
-        u32 offset = bc.iterCache.at(iter);
-        return offset;
-    }
-
-    u32 offset = bc.engine_blob.add(iter.begin(), iter.end());
-
-    bc.iterCache.insert(make_pair(iter, offset));
-
-    return offset;
-}
-
 static
 u32 buildLastByteIter(const RoseGraph &g, build_context &bc) {
     vector<u32> lb_roles;
@@ -2217,7 +2195,7 @@ u32 buildLastByteIter(const RoseGraph &g, build_context &bc) {
 
     vector<mmbit_sparse_iter> iter;
     mmbBuildSparseIterator(iter, lb_roles, bc.numStates);
-    return addIteratorToTable(bc, iter);
+    return bc.engine_blob.add_iterator(iter);
 }
 
 static
@@ -2329,7 +2307,7 @@ u32 buildEodNfaIterator(build_context &bc, const u32 activeQueueCount) {
 
     vector<mmbit_sparse_iter> iter;
     mmbBuildSparseIterator(iter, keys, activeQueueCount);
-    return addIteratorToTable(bc, iter);
+    return bc.engine_blob.add_iterator(iter);
 }
 
 static
@@ -4669,7 +4647,7 @@ u32 buildEagerQueueIter(const set<u32> &eager, u32 leftfixBeginQueue,
 
     vector<mmbit_sparse_iter> iter;
     mmbBuildSparseIterator(iter, vec, queue_count - leftfixBeginQueue);
-    return addIteratorToTable(bc, iter);
+    return bc.engine_blob.add_iterator(iter);
 }
 
 static
diff --git a/src/rose/rose_build_engine_blob.h b/src/rose/rose_build_engine_blob.h
index 0914502e..8542b87b 100644
--- a/src/rose/rose_build_engine_blob.h
+++ b/src/rose/rose_build_engine_blob.h
@@ -34,6 +34,8 @@
 #include "ue2common.h"
 #include "util/alloc.h"
 #include "util/container.h"
+#include "util/multibit_build.h"
+#include "util/ue2_containers.h"
 #include "util/verify_types.h"
 
 #include <vector>
@@ -104,6 +106,19 @@ public:
         return offset;
     }
 
+    u32 add_iterator(const std::vector<mmbit_sparse_iter> &iter) {
+        auto cache_it = cached_iters.find(iter);
+        if (cache_it != cached_iters.end()) {
+            u32 offset = cache_it->second;
+            DEBUG_PRINTF("cache hit for iter at %u\n", offset);
+            return offset;
+        }
+
+        u32 offset = add(iter.begin(), iter.end());
+        cached_iters.emplace(iter, offset);
+        return offset;
+    }
+
     void write_bytes(RoseEngine *engine) {
         copy_bytes((char *)engine + base_offset, blob);
     }
@@ -120,6 +135,9 @@ private:
         blob.resize(s + align - s % align);
     }
 
+    /** \brief Cache of previously-written sparse iterators. */
+    unordered_map<std::vector<mmbit_sparse_iter>, u32> cached_iters;
+
     /**
      * \brief Contents of the Rose bytecode immediately following the
      * RoseEngine.
diff --git a/src/rose/rose_build_program.cpp b/src/rose/rose_build_program.cpp
index 73740976..168022f3 100644
--- a/src/rose/rose_build_program.cpp
+++ b/src/rose/rose_build_program.cpp
@@ -387,7 +387,7 @@ void RoseInstrSparseIterBegin::write(void *dest, RoseEngineBlob &blob,
     vector<mmbit_sparse_iter> iter;
     mmbBuildSparseIterator(iter, keys, num_keys);
     assert(!iter.empty());
-    inst->iter_offset = blob.add(iter.begin(), iter.end());
+    inst->iter_offset = blob.add_iterator(iter);
     inst->jump_table = blob.add(jump_offsets.begin(), jump_offsets.end());
 
     // Store offsets for corresponding SPARSE_ITER_NEXT operations.
@@ -422,7 +422,7 @@ void RoseInstrSparseIterAny::write(void *dest, RoseEngineBlob &blob,
     vector<mmbit_sparse_iter> iter;
     mmbBuildSparseIterator(iter, keys, num_keys);
     assert(!iter.empty());
-    inst->iter_offset = blob.add(iter.begin(), iter.end());
+    inst->iter_offset = blob.add_iterator(iter);
 }
 
 void RoseInstrEnginesEod::write(void *dest, RoseEngineBlob &blob,
diff --git a/src/util/multibit_build.h b/src/util/multibit_build.h
index ac263552..5fbaab87 100644
--- a/src/util/multibit_build.h
+++ b/src/util/multibit_build.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Intel Corporation
+ * Copyright (c) 2015-2016, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -34,16 +34,18 @@
 #define MULTIBIT_BUILD_H
 
 #include "multibit_internal.h"
+#include "hash.h"
 
 #include <vector>
 
-/** \brief Comparator for \ref mmbit_sparse_iter structures. */
-static inline
-bool operator<(const mmbit_sparse_iter &a, const mmbit_sparse_iter &b) {
-    if (a.mask != b.mask) {
-        return a.mask < b.mask;
-    }
-    return a.val < b.val;
+inline
+bool operator==(const mmbit_sparse_iter &a, const mmbit_sparse_iter &b) {
+    return a.mask == b.mask && a.val == b.val;
+}
+
+inline
+size_t hash_value(const mmbit_sparse_iter &iter) {
+    return ue2::hash_all(iter.mask, iter.val);
 }
 
 namespace ue2 {