diff --git a/toolchain/check/context.h b/toolchain/check/context.h
index 6043f716fc2b..0573522fb8d8 100644
--- a/toolchain/check/context.h
+++ b/toolchain/check/context.h
@@ -348,12 +348,9 @@ class Context {
 
   // Directly expose SemIR::File data accessors for brevity in calls.
 
-  // Use `lexical_lookup().AddIdentifier` to add entries. `identifiers()` is
-  // const to discourage misuse.
-  auto identifiers() -> const StringStoreWrapper<IdentifierId>& {
+  auto identifiers() -> StringStoreWrapper<IdentifierId>& {
     return sem_ir().identifiers();
   }
-
   auto ints() -> ValueStore<IntId>& { return sem_ir().ints(); }
   auto reals() -> ValueStore<RealId>& { return sem_ir().reals(); }
   auto string_literal_values() -> StringStoreWrapper<StringLiteralValueId>& {
diff --git a/toolchain/check/import.cpp b/toolchain/check/import.cpp
index b285c72cbef1..ff49ef46f937 100644
--- a/toolchain/check/import.cpp
+++ b/toolchain/check/import.cpp
@@ -57,8 +57,7 @@ static auto CopyNameFromImportIR(Context& context,
   if (auto import_identifier_id = import_name_id.AsIdentifierId();
       import_identifier_id.is_valid()) {
     auto name = import_sem_ir.identifiers().Get(import_identifier_id);
-    return SemIR::NameId::ForIdentifier(
-        context.lexical_lookup().AddIdentifier(name));
+    return SemIR::NameId::ForIdentifier(context.identifiers().Add(name));
   }
   return import_name_id;
 }
diff --git a/toolchain/check/lexical_lookup.h b/toolchain/check/lexical_lookup.h
index 1b8c395ade1b..09ab07e1862f 100644
--- a/toolchain/check/lexical_lookup.h
+++ b/toolchain/check/lexical_lookup.h
@@ -29,36 +29,23 @@ class LexicalLookup {
     ScopeIndex scope_index;
   };
 
-  explicit LexicalLookup(StringStoreWrapper<IdentifierId>& identifiers)
-      : identifiers_(&identifiers),
-        lookup_(identifiers_->size() + SemIR::NameId::NonIndexValueCount) {}
-
-  ~LexicalLookup() {
-    CARBON_CHECK(lookup_.size() ==
-                 identifiers_->size() + SemIR::NameId::NonIndexValueCount)
-        << lookup_.size() << " must match " << identifiers_->size() << " + "
-        << SemIR::NameId::NonIndexValueCount
-        << "; something may have been added incorrectly";
-  }
-
-  // Handles both adding the identifier and resizing lookup_ to accommodate the
-  // new entry. `identifiers().Add` must not be called directly once checking
-  // has begun.
-  auto AddIdentifier(llvm::StringRef name) -> IdentifierId {
-    auto id = identifiers_->Add(name);
-    // Bear in mind that Add was not guaranteed to actually change the size.
-    lookup_.resize(identifiers_->size() + SemIR::NameId::NonIndexValueCount);
-    return id;
-  }
+  explicit LexicalLookup(const StringStoreWrapper<IdentifierId>& identifiers)
+      : lookup_(identifiers.size() + SemIR::NameId::NonIndexValueCount) {}
 
   // Returns the lexical lookup results for a name.
   auto Get(SemIR::NameId name_id) -> llvm::SmallVector<Result, 2>& {
-    return lookup_[name_id.index + SemIR::NameId::NonIndexValueCount];
+    size_t index = name_id.index + SemIR::NameId::NonIndexValueCount;
+    CARBON_CHECK(index < lookup_.size())
+        << "An identifier was added after the Context was initialized. "
+           "Currently, we expect that new identifiers will never be used with "
+           "lexical lookup (they're added for things like detecting name "
+           "collisions in imports). That might change with metaprogramming: if "
+           "it does, we may need to start resizing `lookup_`, either on each "
+           "identifier addition or in Get` where this CHECK currently fires.";
+    return lookup_[index];
   }
 
  private:
-  StringStoreWrapper<IdentifierId>* identifiers_;
-
   // Maps identifiers to name lookup results.
   // TODO: Consider TinyPtrVector<Result> or similar. For now, use a small size
   // of 2 to cover the common case.