Index: libcxx/include/chrono
===================================================================
--- libcxx/include/chrono
+++ libcxx/include/chrono
@@ -1286,10 +1286,43 @@
 {
 };
 
+template <class _Tp, class _Up, class = void>
+struct __has_common_type : false_type {};
+
+template <class _Tp, class _Up>
+struct __has_common_type<_Tp, _Up, typename __void_t<typename common_type<_Tp, _Up>::type>::type> : true_type {};
+
+template <class _Rep1, class _Rep2, bool>
+struct __Fooby2 : false_type {};
+
+template <class _Rep1, class _Rep2>
+struct __Fooby2<_Rep1, _Rep2, true> : _LIBCPP_BOOL_CONSTANT((is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value)) {};
+
+template <class _Rep1, class _Period, class _Rep2, bool>
+struct __Fooby : false_type {};
+
+template <class _Rep1, class _Period, class _Rep2>
+struct __Fooby<_Rep1, _Period, _Rep2, false> : _LIBCPP_BOOL_CONSTANT((__Fooby2<_Rep1, _Rep2, __has_common_type<_Rep1, _Rep2>::value>::value)) {};
+
+template <class _Rep1, class _Period, class _Rep2, bool>
+struct __FoobyRet { typedef void type; };
+
+template <class _Rep1, class _Period, class _Rep2>
+struct __FoobyRet<_Rep1, _Period, _Rep2, true>
+{
+	typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
+};
+
 template <class _Rep1, class _Period, class _Rep2>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+typename enable_if
+<
+//     !__is_duration<_Rep2>::value && is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
+//    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+	__Fooby<_Rep1, _Period, _Rep2, __is_duration<_Rep2>::value>::value,
+	typename __FoobyRet<_Rep1, _Period, _Rep2, __Fooby<_Rep1, _Period, _Rep2, __is_duration<_Rep2>::value>::value>::type
+>::type
 operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
 {
     typedef typename common_type<_Rep1, _Rep2>::type _Cr;
@@ -1312,7 +1345,13 @@
 template <class _Rep1, class _Period, class _Rep2>
 inline _LIBCPP_INLINE_VISIBILITY
 _LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
+typename enable_if
+<
+//     !__is_duration<_Rep2>::value && is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
+//    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
+	__Fooby<_Rep1, _Period, _Rep2, __is_duration<_Rep2>::value>::value,
+	typename __FoobyRet<_Rep1, _Period, _Rep2, __Fooby<_Rep1, _Period, _Rep2, __is_duration<_Rep2>::value>::value>::type
+>::type
 operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
 {
     typedef typename common_type<_Rep1, _Rep2>::type _Cr;
Index: libcxx/test/std/utilities/time/rep.h
===================================================================
--- libcxx/test/std/utilities/time/rep.h
+++ libcxx/test/std/utilities/time/rep.h
@@ -25,4 +25,40 @@
     Rep& operator/=(Rep x) {data_ /= x.data_; return *this;}
 };
 
+// This is PR#41130
+
+struct NotARep {};
+
+// std::chrono:::duration has only '*', '/' and '%' taking a "Rep" parameter
+
+// Multiplication is commutative, division is not.
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>
+operator*(std::chrono::duration<Rep, Period> d, NotARep) { return d; }
+
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>
+operator*(NotARep, std::chrono::duration<Rep, Period> d) { return d; }
+
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>
+operator/(std::chrono::duration<Rep, Period> d, NotARep) { return d; }
+
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>
+operator%(std::chrono::duration<Rep, Period> d, NotARep) { return d; }
+
+// op= is not commutative.
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>&
+operator*=(std::chrono::duration<Rep, Period>& d, NotARep) { return d; }
+
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>&
+operator/=(std::chrono::duration<Rep, Period>& d, NotARep) { return d; }
+
+template <class Rep, class Period>
+std::chrono::duration<Rep, Period>&
+operator%=(std::chrono::duration<Rep, Period>& d, NotARep) { return d; }
+
 #endif  // REP_H
Index: libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_divide=.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_divide=.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_divide=.pass.cpp
@@ -16,6 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 #if TEST_STD_VER > 14
 constexpr bool test_constexpr()
@@ -38,5 +39,14 @@
     static_assert(test_constexpr(), "");
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    std::chrono::nanoseconds d(5);
+    NotARep n;
+    d /= n;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=duration.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=duration.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=duration.pass.cpp
@@ -16,6 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 #if TEST_STD_VER > 14
 constexpr bool test_constexpr()
@@ -42,5 +43,14 @@
     static_assert(test_constexpr(), "");
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    std::chrono::nanoseconds d(5);
+    NotARep n;
+    d %= n;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=rep.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=rep.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_mod=rep.pass.cpp
@@ -17,6 +17,11 @@
 
 #include "test_macros.h"
 
+class NotARep {};
+
+typedef std::chrono::seconds Duration;
+Duration operator%=(Duration d, NotARep) { return d; }
+
 #if TEST_STD_VER > 14
 constexpr bool test_constexpr()
 {
@@ -38,5 +43,15 @@
     static_assert(test_constexpr(), "");
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    Duration d(5);
+    NotARep n;
+    d %= n;
+    assert(d.count() == 5);
+    }
+#endif
+
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_times=.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_times=.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.arithmetic/op_times=.pass.cpp
@@ -16,6 +16,7 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 #if TEST_STD_VER > 14
 constexpr bool test_constexpr()
@@ -38,5 +39,14 @@
     static_assert(test_constexpr(), "");
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    std::chrono::nanoseconds d(5);
+    NotARep n;
+    d *= n;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_divide_rep.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_divide_rep.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_divide_rep.pass.cpp
@@ -19,11 +19,14 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 int main(int, char**)
 {
     {
-    std::chrono::nanoseconds ns(15);
+    typedef std::chrono::nanoseconds Dur;
+    Dur ns(15);
+    ASSERT_SAME_TYPE(Dur, decltype(ns / 5));
     ns = ns / 5;
     assert(ns.count() == 3);
     }
@@ -35,5 +38,16 @@
     }
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    typedef std::chrono::nanoseconds Duration;
+    Duration d(5);
+    NotARep n;
+    ASSERT_SAME_TYPE(Duration, decltype(d / n));
+    d = d / n;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_mod_rep.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_mod_rep.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_mod_rep.pass.cpp
@@ -19,11 +19,14 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 int main(int, char**)
 {
     {
-    std::chrono::nanoseconds ns(15);
+    typedef std::chrono::nanoseconds Dur;
+    Dur ns(15);
+    ASSERT_SAME_TYPE(Dur, decltype(ns % 6));
     ns = ns % 6;
     assert(ns.count() == 3);
     }
@@ -35,5 +38,16 @@
     }
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is PR#41130
+    typedef std::chrono::seconds Duration;
+    Duration d(5);
+    NotARep n;
+    ASSERT_SAME_TYPE(Duration, decltype(d % n));
+    d = d % n;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }
Index: libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_times_rep.pass.cpp
===================================================================
--- libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_times_rep.pass.cpp
+++ libcxx/test/std/utilities/time/time.duration/time.duration.nonmember/op_times_rep.pass.cpp
@@ -24,6 +24,7 @@
 #include <cassert>
 
 #include "test_macros.h"
+#include "../../rep.h"
 
 int main(int, char**)
 {
@@ -34,6 +35,7 @@
     ns = 6 * ns;
     assert(ns.count() == 90);
     }
+
 #if TEST_STD_VER >= 11
     {
     constexpr std::chrono::nanoseconds ns(3);
@@ -44,5 +46,19 @@
     }
 #endif
 
+#if TEST_STD_VER >= 11
+    { // This is related to PR#41130
+    typedef std::chrono::nanoseconds Duration;
+    Duration d(5);
+    NotARep n;
+    ASSERT_SAME_TYPE(Duration, decltype(d * n));
+    ASSERT_SAME_TYPE(Duration, decltype(n * d));
+    d = d * n;
+    assert(d.count() == 5);
+    d = n * d;
+    assert(d.count() == 5);
+    }
+#endif
+
   return 0;
 }