diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index cea6b248c6fa..3d8bf7a4b3b3 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -20,15 +20,15 @@ namespace std
 {
 
 template <class InputIterator, class Predicate>
-    bool
+    constexpr bool     // constexpr in C++20
     all_of(InputIterator first, InputIterator last, Predicate pred);
 
 template <class InputIterator, class Predicate>
-    bool
+    constexpr bool     // constexpr in C++20
     any_of(InputIterator first, InputIterator last, Predicate pred);
 
 template <class InputIterator, class Predicate>
-    bool
+    constexpr bool     // constexpr in C++20
     none_of(InputIterator first, InputIterator last, Predicate pred);
 
 template <class InputIterator, class Function>
@@ -919,7 +919,7 @@ inline _LIBCPP_INLINE_VISIBILITY int __pop_count(unsigned long long __x) {
 // all_of
 
 template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 {
@@ -932,7 +932,7 @@ all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 // any_of
 
 template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 {
@@ -945,7 +945,7 @@ any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 // none_of
 
 template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
 bool
 none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
 {
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.all_of/all_of.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.all_of/all_of.pass.cpp
index c3c348088195..5896b40ae965 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.all_of/all_of.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.all_of/all_of.pass.cpp
@@ -16,16 +16,27 @@
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
 struct test1
 {
-    bool operator()(const int& i) const
+    TEST_CONSTEXPR bool operator()(const int& i) const
     {
         return i % 2 == 0;
     }
 };
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR int test_constexpr() {
+    int ia[] = {2, 4, 6, 8};
+    int ib[] = {2, 4, 5, 8};
+    return  std::all_of(std::begin(ia), std::end(ia), test1())
+        && !std::all_of(std::begin(ib), std::end(ib), test1())
+        ;
+    }
+#endif
+
 int main()
 {
     {
@@ -44,4 +55,8 @@ int main()
         assert(std::all_of(input_iterator<const int*>(ia),
                            input_iterator<const int*>(ia), test1()) == true);
     }
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.any_of/any_of.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.any_of/any_of.pass.cpp
index d096e20d2d27..5256270a3819 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.any_of/any_of.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.any_of/any_of.pass.cpp
@@ -16,16 +16,27 @@
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
 struct test1
 {
-    bool operator()(const int& i) const
+    TEST_CONSTEXPR bool operator()(const int& i) const
     {
         return i % 2 == 0;
     }
 };
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR int test_constexpr() {
+    int ia[] = {2, 4, 6, 8};
+    int ib[] = {1, 3, 5, 7};
+    return  std::any_of(std::begin(ia), std::end(ia), test1())
+        && !std::any_of(std::begin(ib), std::end(ib), test1())
+        ;
+    }
+#endif
+
 int main()
 {
     {
@@ -52,4 +63,8 @@ int main()
         assert(std::any_of(input_iterator<const int*>(ia),
                            input_iterator<const int*>(ia), test1()) == false);
     }
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }
diff --git a/libcxx/test/std/algorithms/alg.nonmodifying/alg.none_of/none_of.pass.cpp b/libcxx/test/std/algorithms/alg.nonmodifying/alg.none_of/none_of.pass.cpp
index f4ea161891b2..f3b8e7781684 100644
--- a/libcxx/test/std/algorithms/alg.nonmodifying/alg.none_of/none_of.pass.cpp
+++ b/libcxx/test/std/algorithms/alg.nonmodifying/alg.none_of/none_of.pass.cpp
@@ -16,16 +16,27 @@
 #include <algorithm>
 #include <cassert>
 
+#include "test_macros.h"
 #include "test_iterators.h"
 
 struct test1
 {
-    bool operator()(const int& i) const
+    TEST_CONSTEXPR bool operator()(const int& i) const
     {
         return i % 2 == 0;
     }
 };
 
+#if TEST_STD_VER > 17
+TEST_CONSTEXPR int test_constexpr() {
+    int ia[] = {1, 3, 6, 7};
+    int ib[] = {1, 3, 5, 7};
+    return !std::none_of(std::begin(ia), std::end(ia), test1())
+        &&  std::none_of(std::begin(ib), std::end(ib), test1())
+        ;
+    }
+#endif
+
 int main()
 {
     {
@@ -52,4 +63,8 @@ int main()
         assert(std::none_of(input_iterator<const int*>(ia),
                             input_iterator<const int*>(ia), test1()) == true);
     }
+
+#if TEST_STD_VER > 17
+    static_assert(test_constexpr());
+#endif
 }