diff --git a/include/llvm/ADT/SmallSet.h b/include/llvm/ADT/SmallSet.h
index 8359c61d084..d52d0f07f9a 100644
--- a/include/llvm/ADT/SmallSet.h
+++ b/include/llvm/ADT/SmallSet.h
@@ -17,70 +17,14 @@
 #include "llvm/ADT/None.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
-#include "llvm/ADT/iterator.h"
 #include "llvm/Support/Compiler.h"
 #include <cstddef>
 #include <functional>
 #include <set>
-#include <type_traits>
 #include <utility>
 
 namespace llvm {
 
-/// SmallSetIterator - This class implements a const_iterator for SmallSet by
-/// delegating to the underlying SmallVector or Set iterators.
-template <typename T, unsigned N, typename C>
-class SmallSetIterator
-    : public iterator_facade_base<SmallSetIterator<T, N, C>,
-                                  std::forward_iterator_tag, T> {
-private:
-  using SetIterTy = typename std::set<T, C>::const_iterator;
-  using VecIterTy = typename SmallVector<T, N>::const_iterator;
-  using SelfTy = SmallSetIterator<T, N, C>;
-
-  /// Iterators to the parts of the SmallSet containing the data. They are set
-  /// depending on isSmall.
-  union {
-    SetIterTy SetIter;
-    VecIterTy VecIter;
-  };
-
-  bool isSmall;
-
-public:
-  SmallSetIterator(SetIterTy SetIter) : SetIter(SetIter), isSmall(false) {
-    // Use static_assert here, as the SmallSetIterator type is incomplete in the
-    // class scope.
-    static_assert(std::is_trivially_destructible<SelfTy>() &&
-                      std::is_trivially_copy_constructible<SelfTy>() &&
-                      std::is_trivially_copy_assignable<SelfTy>() &&
-                      std::is_move_constructible<SelfTy>() &&
-                      std::is_trivially_move_assignable<SelfTy>(),
-                  "SelfTy needs to be trivial copy and move constructors and "
-                  "assignments");
-  }
-
-  SmallSetIterator(VecIterTy VecIter) : VecIter(VecIter), isSmall(true) {}
-
-  bool operator==(const SmallSetIterator &RHS) const {
-    if (isSmall != RHS.isSmall)
-      return false;
-    if (isSmall)
-      return VecIter == RHS.VecIter;
-    return SetIter == RHS.SetIter;
-  }
-
-  SmallSetIterator &operator++() { // Preincrement
-    if (isSmall)
-      VecIter++;
-    else
-      SetIter++;
-    return *this;
-  }
-
-  const T &operator*() const { return isSmall ? *VecIter : *SetIter; }
-};
-
 /// SmallSet - This maintains a set of unique values, optimizing for the case
 /// when the set is small (less than N).  In this case, the set can be
 /// maintained with no mallocs.  If the set gets large, we expand to using an
@@ -106,7 +50,6 @@ class SmallSet {
 
 public:
   using size_type = size_t;
-  using const_iterator = SmallSetIterator<T, N, C>;
 
   SmallSet() = default;
 
@@ -178,18 +121,6 @@ public:
     Set.clear();
   }
 
-  const_iterator begin() const {
-    if (isSmall())
-      return {Vector.begin()};
-    return {Set.begin()};
-  }
-
-  const_iterator end() const {
-    if (isSmall())
-      return {Vector.end()};
-    return {Set.end()};
-  }
-
 private:
   bool isSmall() const { return Set.empty(); }
 
diff --git a/unittests/ADT/SmallSetTest.cpp b/unittests/ADT/SmallSetTest.cpp
index f820c9e5ccf..7608e65674e 100644
--- a/unittests/ADT/SmallSetTest.cpp
+++ b/unittests/ADT/SmallSetTest.cpp
@@ -13,7 +13,6 @@
 
 #include "llvm/ADT/SmallSet.h"
 #include "gtest/gtest.h"
-#include <string>
 
 using namespace llvm;
 
@@ -69,57 +68,3 @@ TEST(SmallSetTest, Erase) {
 
   EXPECT_EQ(0u, s1.count(8));
 }
-
-TEST(SmallSetTest, IteratorInt) {
-  SmallSet<int, 4> s1;
-
-  // Test the 'small' case.
-  for (int i = 0; i < 3; i++)
-    s1.insert(i);
-
-  std::vector<int> V(s1.begin(), s1.end());
-  // Make sure the elements are in the expected order.
-  std::sort(V.begin(), V.end());
-  for (int i = 0; i < 3; i++)
-    EXPECT_EQ(i, V[i]);
-
-  // Test the 'big' case by adding a few more elements to switch to std::set
-  // internally.
-  for (int i = 3; i < 6; i++)
-    s1.insert(i);
-
-  V.assign(s1.begin(), s1.end());
-  // Make sure the elements are in the expected order.
-  std::sort(V.begin(), V.end());
-  for (int i = 0; i < 6; i++)
-    EXPECT_EQ(i, V[i]);
-}
-
-TEST(SmallSetTest, IteratorString) {
-  // Test SmallSetIterator for SmallSet with a type with non-trivial
-  // ctors/dtors.
-  SmallSet<std::string, 2> s1;
-
-  s1.insert("str 1");
-  s1.insert("str 2");
-  s1.insert("str 1");
-
-  std::vector<std::string> V(s1.begin(), s1.end());
-  std::sort(V.begin(), V.end());
-  EXPECT_EQ(2u, s1.size());
-  EXPECT_EQ("str 1", V[0]);
-  EXPECT_EQ("str 2", V[1]);
-
-  s1.insert("str 4");
-  s1.insert("str 0");
-  s1.insert("str 4");
-
-  V.assign(s1.begin(), s1.end());
-  // Make sure the elements are in the expected order.
-  std::sort(V.begin(), V.end());
-  EXPECT_EQ(4u, s1.size());
-  EXPECT_EQ("str 0", V[0]);
-  EXPECT_EQ("str 1", V[1]);
-  EXPECT_EQ("str 2", V[2]);
-  EXPECT_EQ("str 4", V[3]);
-}