diff --git a/include/boost/process/v2/impl/pid.ipp b/include/boost/process/v2/impl/pid.ipp
index 61e848bb..e638fa14 100644
--- a/include/boost/process/v2/impl/pid.ipp
+++ b/include/boost/process/v2/impl/pid.ipp
@@ -147,15 +147,14 @@ std::vector<pid_type> child_pids(pid_type pid, boost::system::error_code & ec)
 std::vector<pid_type> all_pids(boost::system::error_code & ec)
 {
     std::vector<pid_type> vec;
-    vec.reserve(proc_listpids(PROC_ALL_PIDS, 0, nullptr, 0));
-    if (proc_listpids(PROC_ALL_PIDS, 0, &vec[0], sizeof(pid_type) * vec.size()))
+    vec.resize(proc_listpids(PROC_ALL_PIDS, 0, nullptr, 0) / sizeof(pid_type));
+    const auto sz = proc_listpids(PROC_ALL_PIDS, 0, &vec[0], sizeof(pid_type) * vec.size());
+    if (sz < 0)
     {
         BOOST_PROCESS_V2_ASSIGN_LAST_ERROR(ec)
         return {};
     }
-    auto itr = std::partition(vec.begin(), vec.end(), [](pid_type pt) {return pt != 0;});
-    vec.erase(itr, vec.end());
-    std::reverse(vec.begin(), vec.end());
+    vec.resize(sz);
     return vec;
 }
 
@@ -176,15 +175,14 @@ pid_type parent_pid(pid_type pid, boost::system::error_code & ec)
 std::vector<pid_type> child_pids(pid_type pid, boost::system::error_code & ec) 
 {
     std::vector<pid_type> vec;
-    vec.reserve(proc_listpids(PROC_PPID_ONLY, (uint32_t)pid, nullptr, 0));
-    if (proc_listpids(PROC_PPID_ONLY, (uint32_t)pid, &vec[0], sizeof(pid_type) * vec.size()))
+    vec.resize(proc_listpids(PROC_PPID_ONLY, (uint32_t)pid, nullptr, 0) / sizeof(pid_type));
+    const auto sz = proc_listpids(PROC_PPID_ONLY, (uint32_t)pid, &vec[0], sizeof(pid_type) * vec.size());
+    if (sz < 0)
     {
         BOOST_PROCESS_V2_ASSIGN_LAST_ERROR(ec)
         return {};
     }
-    auto itr = std::partition(vec.begin(), vec.end(), [](pid_type pt) {return pt != 0;});
-    vec.erase(itr, vec.end());
-    std::reverse(vec.begin(), vec.end());
+    vec.resize(sz);
     return vec;
 }
 
diff --git a/test/v2/pid.cpp b/test/v2/pid.cpp
index 4102acec..570bc259 100644
--- a/test/v2/pid.cpp
+++ b/test/v2/pid.cpp
@@ -34,6 +34,7 @@ BOOST_AUTO_TEST_CASE(child_pid)
 
     using boost::unit_test::framework::master_test_suite;
     const auto pth = bp2::filesystem::absolute(master_test_suite().argv[1]);
+    std::this_thread::sleep_for(std::chrono::milliseconds(20));
 
     auto cs = bp2::child_pids(bp2::current_pid());
     boost::asio::io_context ctx;