diff --git a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_equal/equal.pass.cpp b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_equal/equal.pass.cpp
index 2005d303fb3b..0137664312de 100644
--- a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_equal/equal.pass.cpp
+++ b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_equal/equal.pass.cpp
@@ -26,26 +26,37 @@ int main()
         std::istreambuf_iterator<char> i2(inf2);
         std::istreambuf_iterator<char> i3;
         std::istreambuf_iterator<char> i4;
+        std::istreambuf_iterator<char> i5(nullptr);
 
         assert( i1.equal(i1));
         assert( i1.equal(i2));
         assert(!i1.equal(i3));
         assert(!i1.equal(i4));
+        assert(!i1.equal(i5));
 
         assert( i2.equal(i1));
         assert( i2.equal(i2));
         assert(!i2.equal(i3));
         assert(!i2.equal(i4));
+        assert(!i2.equal(i5));
 
         assert(!i3.equal(i1));
         assert(!i3.equal(i2));
         assert( i3.equal(i3));
         assert( i3.equal(i4));
+        assert( i3.equal(i5));
 
         assert(!i4.equal(i1));
         assert(!i4.equal(i2));
         assert( i4.equal(i3));
         assert( i4.equal(i4));
+        assert( i4.equal(i5));
+
+        assert(!i5.equal(i1));
+        assert(!i5.equal(i2));
+        assert( i5.equal(i3));
+        assert( i5.equal(i4));
+        assert( i5.equal(i5));
     }
     {
         std::wistringstream inf1(L"abc");
@@ -54,25 +65,36 @@ int main()
         std::istreambuf_iterator<wchar_t> i2(inf2);
         std::istreambuf_iterator<wchar_t> i3;
         std::istreambuf_iterator<wchar_t> i4;
+        std::istreambuf_iterator<wchar_t> i5(nullptr);
 
         assert( i1.equal(i1));
         assert( i1.equal(i2));
         assert(!i1.equal(i3));
         assert(!i1.equal(i4));
+        assert(!i1.equal(i5));
 
         assert( i2.equal(i1));
         assert( i2.equal(i2));
         assert(!i2.equal(i3));
         assert(!i2.equal(i4));
+        assert(!i2.equal(i5));
 
         assert(!i3.equal(i1));
         assert(!i3.equal(i2));
         assert( i3.equal(i3));
         assert( i3.equal(i4));
+        assert( i3.equal(i5));
 
         assert(!i4.equal(i1));
         assert(!i4.equal(i2));
         assert( i4.equal(i3));
         assert( i4.equal(i4));
+        assert( i4.equal(i5));
+
+        assert(!i5.equal(i1));
+        assert(!i5.equal(i2));
+        assert( i5.equal(i3));
+        assert( i5.equal(i4));
+        assert( i5.equal(i5));
     }
 }
diff --git a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op!=/not_equal.pass.cpp b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op!=/not_equal.pass.cpp
index 5e8536423d8b..81e5f3439fe6 100644
--- a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op!=/not_equal.pass.cpp
+++ b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op!=/not_equal.pass.cpp
@@ -28,26 +28,37 @@ int main()
         std::istreambuf_iterator<char> i2(inf2);
         std::istreambuf_iterator<char> i3;
         std::istreambuf_iterator<char> i4;
+        std::istreambuf_iterator<char> i5(nullptr);
 
         assert(!(i1 != i1));
         assert(!(i1 != i2));
         assert( (i1 != i3));
         assert( (i1 != i4));
+        assert( (i1 != i5));
 
         assert(!(i2 != i1));
         assert(!(i2 != i2));
         assert( (i2 != i3));
         assert( (i2 != i4));
+        assert( (i2 != i5));
 
         assert( (i3 != i1));
         assert( (i3 != i2));
         assert(!(i3 != i3));
         assert(!(i3 != i4));
+        assert(!(i3 != i5));
 
         assert( (i4 != i1));
         assert( (i4 != i2));
         assert(!(i4 != i3));
         assert(!(i4 != i4));
+        assert(!(i4 != i5));
+
+        assert( (i5 != i1));
+        assert( (i5 != i2));
+        assert(!(i5 != i3));
+        assert(!(i5 != i4));
+        assert(!(i5 != i5));
     }
     {
         std::wistringstream inf1(L"abc");
@@ -56,25 +67,36 @@ int main()
         std::istreambuf_iterator<wchar_t> i2(inf2);
         std::istreambuf_iterator<wchar_t> i3;
         std::istreambuf_iterator<wchar_t> i4;
+        std::istreambuf_iterator<wchar_t> i5(nullptr);
 
         assert(!(i1 != i1));
         assert(!(i1 != i2));
         assert( (i1 != i3));
         assert( (i1 != i4));
+        assert( (i1 != i5));
 
         assert(!(i2 != i1));
         assert(!(i2 != i2));
         assert( (i2 != i3));
         assert( (i2 != i4));
+        assert( (i2 != i5));
 
         assert( (i3 != i1));
         assert( (i3 != i2));
         assert(!(i3 != i3));
         assert(!(i3 != i4));
+        assert(!(i3 != i5));
 
         assert( (i4 != i1));
         assert( (i4 != i2));
         assert(!(i4 != i3));
         assert(!(i4 != i4));
+        assert(!(i4 != i5));
+
+        assert( (i5 != i1));
+        assert( (i5 != i2));
+        assert(!(i5 != i3));
+        assert(!(i5 != i4));
+        assert(!(i5 != i5));
     }
 }
diff --git a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op==/equal.pass.cpp b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op==/equal.pass.cpp
index 919576920ef5..65a78cb104a8 100644
--- a/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op==/equal.pass.cpp
+++ b/libcxx/test/std/iterators/stream.iterators/istreambuf.iterator/istreambuf.iterator_op==/equal.pass.cpp
@@ -28,26 +28,37 @@ int main()
         std::istreambuf_iterator<char> i2(inf2);
         std::istreambuf_iterator<char> i3;
         std::istreambuf_iterator<char> i4;
+        std::istreambuf_iterator<char> i5(nullptr);
 
         assert( (i1 == i1));
         assert( (i1 == i2));
         assert(!(i1 == i3));
         assert(!(i1 == i4));
+        assert(!(i1 == i5));
 
         assert( (i2 == i1));
         assert( (i2 == i2));
         assert(!(i2 == i3));
         assert(!(i2 == i4));
+        assert(!(i2 == i5));
 
         assert(!(i3 == i1));
         assert(!(i3 == i2));
         assert( (i3 == i3));
         assert( (i3 == i4));
+        assert( (i3 == i5));
 
         assert(!(i4 == i1));
         assert(!(i4 == i2));
         assert( (i4 == i3));
         assert( (i4 == i4));
+        assert( (i4 == i5));
+
+        assert(!(i5 == i1));
+        assert(!(i5 == i2));
+        assert( (i5 == i3));
+        assert( (i5 == i4));
+        assert( (i5 == i5));
     }
     {
         std::wistringstream inf1(L"abc");
@@ -56,25 +67,36 @@ int main()
         std::istreambuf_iterator<wchar_t> i2(inf2);
         std::istreambuf_iterator<wchar_t> i3;
         std::istreambuf_iterator<wchar_t> i4;
+        std::istreambuf_iterator<wchar_t> i5(nullptr);
 
         assert( (i1 == i1));
         assert( (i1 == i2));
         assert(!(i1 == i3));
         assert(!(i1 == i4));
+        assert(!(i1 == i5));
 
         assert( (i2 == i1));
         assert( (i2 == i2));
         assert(!(i2 == i3));
         assert(!(i2 == i4));
+        assert(!(i2 == i5));
 
         assert(!(i3 == i1));
         assert(!(i3 == i2));
         assert( (i3 == i3));
         assert( (i3 == i4));
+        assert( (i3 == i5));
 
         assert(!(i4 == i1));
         assert(!(i4 == i2));
         assert( (i4 == i3));
         assert( (i4 == i4));
+        assert( (i4 == i5));
+
+        assert(!(i5 == i1));
+        assert(!(i5 == i2));
+        assert( (i5 == i3));
+        assert( (i5 == i4));
+        assert( (i5 == i5));
     }
 }