diff --git a/enzyme/Enzyme/TypeAnalysis/TypeTree.h b/enzyme/Enzyme/TypeAnalysis/TypeTree.h
index 0a3611e7e2a3..d0eb235dea6e 100644
--- a/enzyme/Enzyme/TypeAnalysis/TypeTree.h
+++ b/enzyme/Enzyme/TypeAnalysis/TypeTree.h
@@ -1240,35 +1240,36 @@ class TypeTree : public std::enable_shared_from_this<TypeTree> {
   /// equivalent If this is an illegal operation, `LegalOr` will be set to false
   bool checkedOrIn(const TypeTree &RHS, bool PointerIntSame, bool &LegalOr) {
     // Add fast path where nothing could change because all potentially inserted
-    // value are already in the map
-    {
-      bool newval = false;
-      for (const auto &pair : RHS.mapping) {
-        auto found = mapping.find(pair.first);
-        if (found == mapping.end()) {
-          newval = true;
-          break;
-        }
-        bool SubLegalOr = true;
-        auto cur = found->second;
-        bool SubChanged =
-            cur.checkedOrIn(pair.second, PointerIntSame, SubLegalOr);
-        if (!SubLegalOr) {
-          LegalOr = false;
-          return false;
-        }
-        if (!SubChanged) {
-          newval = true;
-          break;
-        }
+    // value are already in the map. Save all other ones that may need slow
+    // insertion
+    std::vector<std::pair<const std::vector<int>, ConcreteType>> todo;
+
+    for (const auto &pair : RHS.mapping) {
+      auto found = mapping.find(pair.first);
+      if (found == mapping.end()) {
+        todo.emplace_back(pair);
+        continue;
       }
-      if (!newval)
+      bool SubLegalOr = true;
+      auto cur = found->second;
+      bool SubChanged =
+          cur.checkedOrIn(pair.second, PointerIntSame, SubLegalOr);
+      if (!SubLegalOr) {
+        LegalOr = false;
         return false;
+      }
+      if (!SubChanged) {
+        todo.emplace_back(pair);
+        continue;
+      }
     }
 
+    if (todo.size() == 0)
+      return false;
+
     // TODO detect recursive merge and simplify
     bool changed = false;
-    for (auto &pair : RHS.mapping) {
+    for (auto &pair : todo) {
       changed |= checkedOrIn(pair.first, pair.second, PointerIntSame, LegalOr);
     }
     return changed;