diff --git a/gcc/rust/ast/rust-collect-lang-items.cc b/gcc/rust/ast/rust-collect-lang-items.cc
index 308720ae69ab..50d134a429f5 100644
--- a/gcc/rust/ast/rust-collect-lang-items.cc
+++ b/gcc/rust/ast/rust-collect-lang-items.cc
@@ -82,5 +82,13 @@ CollectLangItems::visit (AST::TraitItemType &item)
   DefaultASTVisitor::visit (item);
 }
 
+void
+CollectLangItems::visit (AST::Function &item)
+{
+  maybe_add_lang_item (item);
+
+  DefaultASTVisitor::visit (item);
+}
+
 } // namespace AST
 } // namespace Rust
diff --git a/gcc/rust/ast/rust-collect-lang-items.h b/gcc/rust/ast/rust-collect-lang-items.h
index 552648f04eda..1d021b1d9c50 100644
--- a/gcc/rust/ast/rust-collect-lang-items.h
+++ b/gcc/rust/ast/rust-collect-lang-items.h
@@ -47,6 +47,7 @@ class CollectLangItems : public DefaultASTVisitor
 
   void visit (AST::Trait &item) override;
   void visit (AST::TraitItemType &item) override;
+  void visit (AST::Function &item) override;
 
 private:
   template <typename T> void maybe_add_lang_item (const T &item);
diff --git a/gcc/rust/util/rust-lang-item.cc b/gcc/rust/util/rust-lang-item.cc
index 0d8a98077d1e..8b1b1e346474 100644
--- a/gcc/rust/util/rust-lang-item.cc
+++ b/gcc/rust/util/rust-lang-item.cc
@@ -91,6 +91,12 @@ const BiMap<std::string, LangItem::Kind> Rust::LangItem::lang_items = {{
   {"str", Kind::STR},
   {"f32_runtime", Kind::F32_RUNTIME},
   {"f64_runtime", Kind::F64_RUNTIME},
+
+  {"Some", Kind::OPTION_SOME},
+  {"None", Kind::OPTION_NONE},
+
+  {"into_iter", Kind::INTOITER_INTOITER},
+  {"next", Kind::ITERATOR_NEXT},
 }};
 
 tl::optional<LangItem::Kind>
diff --git a/gcc/rust/util/rust-lang-item.h b/gcc/rust/util/rust-lang-item.h
index bcf41df559e5..4b0217616783 100644
--- a/gcc/rust/util/rust-lang-item.h
+++ b/gcc/rust/util/rust-lang-item.h
@@ -26,6 +26,9 @@ namespace Rust {
 class LangItem
 {
 public:
+  // FIXME: We should clean up that enum to make it more inline with the list of
+  // lang-items in Rust 1.49
+  // https://github.com/rust-lang/rust/blob/1.49.0/compiler/rustc_hir/src/lang_items.rs
   enum class Kind
   {
     // https://github.com/rust-lang/rust/blob/master/library/core/src/ops/arith.rs
@@ -116,6 +119,12 @@ class LangItem
     STR,
     F32_RUNTIME,
     F64_RUNTIME,
+
+    OPTION_SOME,
+    OPTION_NONE,
+
+    INTOITER_INTOITER,
+    ITERATOR_NEXT,
   };
 
   static const BiMap<std::string, Kind> lang_items;