diff --git a/include/stdexec/__detail/__basic_sender.hpp b/include/stdexec/__detail/__basic_sender.hpp
index ac552923e..176939e2f 100644
--- a/include/stdexec/__detail/__basic_sender.hpp
+++ b/include/stdexec/__detail/__basic_sender.hpp
@@ -182,7 +182,7 @@ namespace STDEXEC {
       using __tag_t = __decay_t<_Sexpr>::__tag_t;
       using __state_t = __state_type_t<__tag_t, _Sexpr, _Receiver>;
 
-      explicit __op_base(_Sexpr&& __sndr, _Receiver&& __rcvr) noexcept(noexcept(
+      explicit constexpr __op_base(_Sexpr&& __sndr, _Receiver&& __rcvr) noexcept(noexcept(
         __state_t(__sexpr_impl<__tag_t>::get_state(__declval<_Sexpr>(), __declval<_Receiver>()))))
         : __state_(
             __sexpr_impl<__tag_t>::get_state(
@@ -220,7 +220,7 @@ namespace STDEXEC {
         return __impl{__op_}(__indices_for<_Child...>(), static_cast<_Child&&>(__child)...);
       }
 
-      auto operator()(__ignore, __ignore) const noexcept -> __tuple<> {
+      constexpr auto operator()(__ignore, __ignore) const noexcept -> __tuple<> {
         return {};
       }
 
@@ -290,7 +290,7 @@ namespace STDEXEC {
     using __state_t = __op_state::__op_base::__state_t;
     using __inner_ops_t = __apply_result_t<__detail::__connect_fn<_Sexpr, _Receiver>, _Sexpr>;
 
-    explicit __op_state(_Sexpr&& __sexpr, _Receiver __rcvr) noexcept(
+    explicit constexpr __op_state(_Sexpr&& __sexpr, _Receiver __rcvr) noexcept(
       __nothrow_constructible_from<__detail::__op_base<_Sexpr, _Receiver>, _Sexpr, _Receiver>
       && __nothrow_applicable<__detail::__connect_fn<_Sexpr, _Receiver>, _Sexpr>)
       : __op_state::__op_base{static_cast<_Sexpr&&>(__sexpr), static_cast<_Receiver&&>(__rcvr)}
@@ -299,7 +299,7 @@ namespace STDEXEC {
           static_cast<_Sexpr&&>(__sexpr))) {
     }
 
-    STDEXEC_ATTRIBUTE(always_inline) void start() & noexcept {
+    STDEXEC_ATTRIBUTE(always_inline) constexpr void start() & noexcept {
       using __tag_t = __op_state::__tag_t;
       STDEXEC::__apply(
         [&](auto&... __ops) noexcept { __sexpr_impl<__tag_t>::start(this->__state_, __ops...); },
diff --git a/include/stdexec/__detail/__domain.hpp b/include/stdexec/__detail/__domain.hpp
index 9b44ac56c..690aef218 100644
--- a/include/stdexec/__detail/__domain.hpp
+++ b/include/stdexec/__detail/__domain.hpp
@@ -69,7 +69,7 @@ namespace STDEXEC {
 
     template <class _OpTag, class _Sender, class _Env>
     STDEXEC_ATTRIBUTE(always_inline)
-    auto transform_sender(_OpTag, _Sender&& __sndr, const _Env&) const
+    constexpr auto transform_sender(_OpTag, _Sender&& __sndr, const _Env&) const
       noexcept(__nothrow_move_constructible<_Sender>) -> _Sender {
       return static_cast<_Sender>(static_cast<_Sender&&>(__sndr));
     }
diff --git a/include/stdexec/__detail/__just.hpp b/include/stdexec/__detail/__just.hpp
index fdd20c115..4ffbf350e 100644
--- a/include/stdexec/__detail/__just.hpp
+++ b/include/stdexec/__detail/__just.hpp
@@ -68,7 +68,7 @@ namespace STDEXEC {
 
       template <__movable_value... _Ts>
       STDEXEC_ATTRIBUTE(host, device)
-      auto operator()(_Ts&&... __ts) const noexcept(__nothrow_decay_copyable<_Ts...>) {
+      constexpr auto operator()(_Ts&&... __ts) const noexcept(__nothrow_decay_copyable<_Ts...>) {
         return __make_sexpr<just_t>(__tuple{static_cast<_Ts&&>(__ts)...});
       }
     };
diff --git a/include/stdexec/__detail/__operation_states.hpp b/include/stdexec/__detail/__operation_states.hpp
index d2dbca969..0ea0123bd 100644
--- a/include/stdexec/__detail/__operation_states.hpp
+++ b/include/stdexec/__detail/__operation_states.hpp
@@ -37,7 +37,7 @@ namespace STDEXEC {
       template <class _Op>
         requires __has_start<_Op>
       STDEXEC_ATTRIBUTE(always_inline)
-      void operator()(_Op &__op) const noexcept {
+      constexpr void operator()(_Op &__op) const noexcept {
         static_assert(noexcept(__op.start()), "start() members must be noexcept");
         static_assert(__same_as<decltype(__op.start()), void>, "start() members must return void");
         __op.start();
diff --git a/include/stdexec/__detail/__receivers.hpp b/include/stdexec/__detail/__receivers.hpp
index 1a01d6a97..a6abdf32b 100644
--- a/include/stdexec/__detail/__receivers.hpp
+++ b/include/stdexec/__detail/__receivers.hpp
@@ -61,7 +61,7 @@ namespace STDEXEC {
       template <class _Receiver, class... _As>
         requires __set_value_member<_Receiver, _As...>
       STDEXEC_ATTRIBUTE(host, device, always_inline)
-      void operator()(_Receiver &&__rcvr, _As &&...__as) const noexcept {
+      constexpr void operator()(_Receiver &&__rcvr, _As &&...__as) const noexcept {
         static_assert(
           noexcept(static_cast<_Receiver &&>(__rcvr).set_value(static_cast<_As &&>(__as)...)),
           "set_value member functions must be noexcept");
diff --git a/include/stdexec/__detail/__utility.hpp b/include/stdexec/__detail/__utility.hpp
index f45f76b35..f9afcc015 100644
--- a/include/stdexec/__detail/__utility.hpp
+++ b/include/stdexec/__detail/__utility.hpp
@@ -141,7 +141,7 @@ namespace STDEXEC {
   // A derived-to-base cast that works even when the base is not accessible from derived.
   template <class _Tp, class _Up>
   STDEXEC_ATTRIBUTE(host, device)
-  auto __c_upcast(_Up&& u) noexcept -> __copy_cvref_t<_Up&&, _Tp>
+  constexpr auto __c_upcast(_Up&& u) noexcept -> __copy_cvref_t<_Up&&, _Tp>
     requires __decays_to<_Tp, _Tp>
   {
     static_assert(STDEXEC_IS_BASE_OF(_Tp, __decay_t<_Up>));
diff --git a/test/stdexec/algos/factories/test_just.cpp b/test/stdexec/algos/factories/test_just.cpp
index a19c34c69..cc2c26f4e 100644
--- a/test/stdexec/algos/factories/test_just.cpp
+++ b/test/stdexec/algos/factories/test_just.cpp
@@ -181,4 +181,14 @@ namespace {
     ::STDEXEC::start(op);
     CHECK(invoked == 1);
   }
+
+  TEST_CASE("just compile time", "[not][sure]") {
+    static_assert([](const double value) constexpr -> double {
+      auto sndr = ::STDEXEC::just(value);
+      double placeholder = 0;
+      auto opstate = ::STDEXEC::connect(std::move(sndr), expect_value_receiver_ex{placeholder});
+      ::STDEXEC::start(opstate);
+      return placeholder;
+    }(42) == 42);
+  }
 } // namespace
diff --git a/test/test_common/receivers.hpp b/test/test_common/receivers.hpp
index 96185526e..e21c246da 100644
--- a/test/test_common/receivers.hpp
+++ b/test/test_common/receivers.hpp
@@ -218,7 +218,7 @@ namespace {
    public:
     using receiver_concept = STDEXEC::receiver_t;
 
-    explicit expect_value_receiver_ex(T& dest)
+    explicit constexpr expect_value_receiver_ex(T& dest)
       : dest_(&dest) {
     }
 
@@ -227,7 +227,7 @@ namespace {
       , env_(std::move(env)) {
     }
 
-    void set_value(T val) noexcept {
+    constexpr void set_value(T val) noexcept {
       *dest_ = val;
     }
 
@@ -244,7 +244,7 @@ namespace {
       FAIL_CHECK("set_error called on expect_value_receiver_ex");
     }
 
-    auto get_env() const noexcept -> Env {
+    constexpr auto get_env() const noexcept -> Env {
       return env_;
     }
   };