diff --git a/builtin-functions/kphp-light/functions.txt b/builtin-functions/kphp-light/functions.txt
index 40fa259d2e..0ab5a3dfee 100644
--- a/builtin-functions/kphp-light/functions.txt
+++ b/builtin-functions/kphp-light/functions.txt
@@ -85,7 +85,7 @@ function wait(future<any> | false $id, float $timeout = -1.0) ::: ^1[*] | null;
 function sched_yield() ::: void;
 
 /** @kphp-extern-func-info interruptible */
-function sched_yield_sleep($timeout_ns ::: int) ::: void;
+function sched_yield_sleep($duration ::: float) ::: void;
 
 // === Rpc ========================================================================================
 
diff --git a/compiler/code-gen/declarations.cpp b/compiler/code-gen/declarations.cpp
index 79c441ee2a..c3b0359b83 100644
--- a/compiler/code-gen/declarations.cpp
+++ b/compiler/code-gen/declarations.cpp
@@ -72,9 +72,7 @@ void FunctionDeclaration::compile(CodeGenerator &W) const {
   switch (style) {
     case gen_out_style::tagger:
     case gen_out_style::cpp: {
-      if (function->is_k2_fork) {
-        FunctionSignatureGenerator(W) << "task_t<fork_result> " << FunctionName(function) << "(" << params_gen << ")";
-      } else if (function->is_interruptible) {
+      if (function->is_interruptible) {
         FunctionSignatureGenerator(W) << "task_t<" << ret_type_gen << ">" << " " << FunctionName(function) << "(" << params_gen << ")";
       } else {
         FunctionSignatureGenerator(W) << ret_type_gen << " " << FunctionName(function) << "(" << params_gen << ")";
diff --git a/compiler/code-gen/vertex-compiler.cpp b/compiler/code-gen/vertex-compiler.cpp
index b13f5b062f..177251ae87 100644
--- a/compiler/code-gen/vertex-compiler.cpp
+++ b/compiler/code-gen/vertex-compiler.cpp
@@ -849,7 +849,7 @@ void compile_func_call(VertexAdaptor<op_func_call> root, CodeGenerator &W, func_
 
     if (mode == func_call_mode::fork_call) {
       if (func->is_interruptible) {
-        W << "(co_await start_fork_t{" << FunctionName(func);
+        W << "(co_await start_fork_t{static_cast<task_t<void>>(" << FunctionName(func);
       } else {
         W << FunctionForkName(func);
       }
@@ -883,9 +883,7 @@ void compile_func_call(VertexAdaptor<op_func_call> root, CodeGenerator &W, func_
   W << ")";
   if (func->is_interruptible) {
     if (mode == func_call_mode::fork_call) {
-      W << ", start_fork_t::execution::fork})";
-    } else if (func->is_k2_fork) { // k2 fork's return type is 'task_t<fork_result>' so we need to unpack actual result from fork_result
-      W << ").get_result<" << TypeName(tinf::get_type(root)) << ">()";
+      W << "), start_fork_t::execution::fork})";
     } else {
       W << ")";
     }
diff --git a/runtime-core/utils/small-object-storage.h b/runtime-core/utils/small-object-storage.h
index 2ea08dbfe7..efa7f9ecf6 100644
--- a/runtime-core/utils/small-object-storage.h
+++ b/runtime-core/utils/small-object-storage.h
@@ -9,7 +9,7 @@
 #include <type_traits>
 #include <utility>
 
-#include "runtime-core/runtime-core.h"
+#include "runtime-core/allocator/runtime-allocator.h"
 
 template<size_t limit>
 union small_object_storage {
diff --git a/runtime-light/allocator/runtime-light-allocator.cpp b/runtime-light/allocator/runtime-light-allocator.cpp
index 50ac7625c0..6895e1a1e2 100644
--- a/runtime-light/allocator/runtime-light-allocator.cpp
+++ b/runtime-light/allocator/runtime-light-allocator.cpp
@@ -5,9 +5,8 @@
 #include <cstddef>
 #include <cstring>
 
-#include "runtime-core/runtime-core.h"
+#include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/component/component.h"
-#include "runtime-light/utils/panic.h"
 
 namespace {
 // TODO: make it depend on max chunk size, e.g. MIN_EXTRA_MEM_SIZE = f(MAX_CHUNK_SIZE);
@@ -136,4 +135,4 @@ void *RuntimeAllocator::realloc_global_memory(void *mem, size_t new_size, size_t
 
 void RuntimeAllocator::free_global_memory(void *mem, size_t) noexcept {
   get_platform_context()->allocator.free(mem);
-}
\ No newline at end of file
+}
diff --git a/runtime-light/coroutine/awaitable.h b/runtime-light/coroutine/awaitable.h
index c27ab80eb3..f55d2f1228 100644
--- a/runtime-light/coroutine/awaitable.h
+++ b/runtime-light/coroutine/awaitable.h
@@ -19,7 +19,6 @@
 #include "runtime-light/header.h"
 #include "runtime-light/scheduler/scheduler.h"
 #include "runtime-light/stdlib/fork/fork-context.h"
-#include "runtime-light/stdlib/fork/fork.h"
 #include "runtime-light/utils/context.h"
 
 template<class T>
@@ -277,7 +276,7 @@ class start_fork_t {
   SuspendToken suspend_token{std::noop_coroutine(), WaitEvent::Rechedule{}};
 
 public:
-  explicit start_fork_t(task_t<fork_result> &&task_, execution exec_policy_) noexcept
+  explicit start_fork_t(task_t<void> task_, execution exec_policy_) noexcept
     : exec_policy(exec_policy_)
     , fork_coro(task_.get_handle())
     , fork_id(ForkComponentContext::get().push_fork(std::move(task_))) {}
@@ -328,13 +327,16 @@ class start_fork_t {
 template<typename T>
 class wait_fork_t {
   int64_t fork_id;
-  task_t<fork_result> fork_task;
-  task_t<fork_result>::awaiter_t fork_awaiter;
+  task_t<T> fork_task;
+  task_t<T>::awaiter_t fork_awaiter;
+
+  using fork_resume_t = decltype(fork_awaiter.await_resume());
+  using await_resume_t = fork_resume_t;
 
 public:
   explicit wait_fork_t(int64_t fork_id_) noexcept
     : fork_id(fork_id_)
-    , fork_task(ForkComponentContext::get().pop_fork(fork_id))
+    , fork_task(static_cast<task_t<T>>(ForkComponentContext::get().pop_fork(fork_id)))
     , fork_awaiter(std::addressof(fork_task)) {}
 
   wait_fork_t(wait_fork_t &&other) noexcept
@@ -355,8 +357,12 @@ class wait_fork_t {
     fork_awaiter.await_suspend(coro);
   }
 
-  T await_resume() noexcept {
-    return fork_awaiter.await_resume().get_result<T>();
+  await_resume_t await_resume() noexcept {
+    if constexpr (std::is_void_v<await_resume_t>) {
+      fork_awaiter.await_resume();
+    } else {
+      return fork_awaiter.await_resume();
+    }
   }
 
   constexpr bool resumable() const noexcept {
diff --git a/runtime-light/coroutine/task.h b/runtime-light/coroutine/task.h
index ae368e9b63..db8dff5c08 100644
--- a/runtime-light/coroutine/task.h
+++ b/runtime-light/coroutine/task.h
@@ -5,6 +5,7 @@
 #pragma once
 
 #include <cassert>
+#include <concepts>
 #include <coroutine>
 #include <optional>
 #include <utility>
@@ -62,7 +63,6 @@ struct task_t : public task_base_t {
   struct promise_void_t;
 
   using promise_type = std::conditional_t<!std::is_void<T>{}, promise_non_void_t<T>, promise_void_t>;
-
   using task_base_t::task_base_t;
 
   struct promise_base_t {
@@ -225,4 +225,16 @@ struct task_t : public task_base_t {
   std::coroutine_handle<promise_type> get_handle() {
     return std::coroutine_handle<promise_type>::from_address(handle_address);
   }
+
+  // conversion functions
+  //
+  // erase type
+  explicit operator task_t<void>() && noexcept {
+    return task_t<void>{std::coroutine_handle<>::from_address(std::exchange(handle_address, nullptr))};
+  }
+  // restore erased type
+  template<typename U>
+  requires(std::same_as<void, T>) explicit operator task_t<U>() && noexcept {
+    return task_t<U>{std::coroutine_handle<>::from_address(std::exchange(handle_address, nullptr))};
+  }
 };
diff --git a/runtime-light/stdlib/fork/fork-api.cpp b/runtime-light/stdlib/fork/fork-api.cpp
index b8e68746ce..fca25d4357 100644
--- a/runtime-light/stdlib/fork/fork-api.cpp
+++ b/runtime-light/stdlib/fork/fork-api.cpp
@@ -5,7 +5,6 @@
 #include "runtime-light/stdlib/fork/fork-api.h"
 
 #include <chrono>
-#include <cstdint>
 
 #include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/coroutine/awaitable.h"
@@ -15,10 +14,10 @@ task_t<void> f$sched_yield() noexcept {
   co_await wait_for_reschedule_t{};
 }
 
-task_t<void> f$sched_yield_sleep(int64_t duration_ns) noexcept {
-  if (duration_ns < 0) {
-    php_warning("can't sleep for negative duration %" PRId64, duration_ns);
+task_t<void> f$sched_yield_sleep(double duration) noexcept {
+  if (duration <= 0) {
+    php_warning("can't sleep for negative or zero duration %.9f", duration);
     co_return;
   }
-  co_await wait_for_timer_t{std::chrono::nanoseconds{static_cast<uint64_t>(duration_ns)}};
+  co_await wait_for_timer_t{std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::duration<double>{duration})};
 }
diff --git a/runtime-light/stdlib/fork/fork-api.h b/runtime-light/stdlib/fork/fork-api.h
index 99b3fa2167..55e05d0fe4 100644
--- a/runtime-light/stdlib/fork/fork-api.h
+++ b/runtime-light/stdlib/fork/fork-api.h
@@ -5,9 +5,11 @@
 #pragma once
 
 #include <chrono>
+#include <concepts>
 #include <cstdint>
 
 #include "runtime-core/core-types/decl/optional.h"
+#include "runtime-core/runtime-core.h"
 #include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/coroutine/awaitable.h"
 #include "runtime-light/coroutine/task.h"
@@ -23,7 +25,7 @@ constexpr auto DEFAULT_TIMEOUT_NS = std::chrono::duration_cast<std::chrono::nano
 } // namespace fork_api_impl_
 
 template<typename T>
-requires(is_optional<T>::value) task_t<T> f$wait(int64_t fork_id, double timeout = -1.0) noexcept {
+requires(is_optional<T>::value || std::same_as<T, mixed>) task_t<T> f$wait(int64_t fork_id, double timeout = -1.0) noexcept {
   auto &fork_ctx{ForkComponentContext::get()};
   if (!fork_ctx.contains(fork_id)) {
     php_warning("can't find fork %" PRId64, fork_id);
@@ -38,10 +40,10 @@ requires(is_optional<T>::value) task_t<T> f$wait(int64_t fork_id, double timeout
 }
 
 template<typename T>
-requires(is_optional<T>::value) task_t<T> f$wait(Optional<int64_t> fork_id_opt, double timeout = -1.0) noexcept {
+requires(is_optional<T>::value || std::same_as<T, mixed>) task_t<T> f$wait(Optional<int64_t> fork_id_opt, double timeout = -1.0) noexcept {
   co_return co_await f$wait<T>(fork_id_opt.has_value() ? fork_id_opt.val() : INVALID_FORK_ID, timeout);
 }
 
 task_t<void> f$sched_yield() noexcept;
 
-task_t<void> f$sched_yield_sleep(int64_t duration_ns) noexcept;
+task_t<void> f$sched_yield_sleep(double duration) noexcept;
diff --git a/runtime-light/stdlib/fork/fork-context.h b/runtime-light/stdlib/fork/fork-context.h
index 57c67ec1af..0788204439 100644
--- a/runtime-light/stdlib/fork/fork-context.h
+++ b/runtime-light/stdlib/fork/fork-context.h
@@ -10,7 +10,6 @@
 #include "runtime-core/memory-resource/unsynchronized_pool_resource.h"
 #include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/coroutine/task.h"
-#include "runtime-light/stdlib/fork/fork.h"
 #include "runtime-light/utils/concepts.h"
 
 constexpr int64_t INVALID_FORK_ID = -1;
@@ -20,15 +19,15 @@ class ForkComponentContext {
   using unordered_map = memory_resource::stl::unordered_map<Key, Value, memory_resource::unsynchronized_pool_resource>;
 
   static constexpr auto FORK_ID_INIT = 0;
-
-  unordered_map<int64_t, task_t<fork_result>> forks;
+  // type erased tasks that represent forks
+  unordered_map<int64_t, task_t<void>> forks;
   int64_t next_fork_id{FORK_ID_INIT + 1};
 
-  int64_t push_fork(task_t<fork_result> &&task) noexcept {
+  int64_t push_fork(task_t<void> task) noexcept {
     return forks.emplace(next_fork_id, std::move(task)), next_fork_id++;
   }
 
-  task_t<fork_result> pop_fork(int64_t fork_id) noexcept {
+  task_t<void> pop_fork(int64_t fork_id) noexcept {
     const auto it_fork{forks.find(fork_id)};
     if (it_fork == forks.end()) {
       php_critical_error("can't find fork %" PRId64, fork_id);
@@ -44,7 +43,7 @@ class ForkComponentContext {
 
 public:
   explicit ForkComponentContext(memory_resource::unsynchronized_pool_resource &memory_resource) noexcept
-    : forks(unordered_map<int64_t, task_t<fork_result>>::allocator_type{memory_resource}) {}
+    : forks(unordered_map<int64_t, task_t<void>>::allocator_type{memory_resource}) {}
 
   static ForkComponentContext &get() noexcept;
 
diff --git a/runtime-light/stdlib/fork/fork.h b/runtime-light/stdlib/fork/fork.h
deleted file mode 100644
index 0837de8d38..0000000000
--- a/runtime-light/stdlib/fork/fork.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// Compiler for PHP (aka KPHP)
-// Copyright (c) 2024 LLC «V Kontakte»
-// Distributed under the GPL v3 License, see LICENSE.notice.txt
-
-#pragma once
-
-#include <concepts>
-#include <type_traits>
-#include <utility>
-
-#include "runtime-core/runtime-core.h"
-#include "runtime-core/utils/small-object-storage.h"
-
-class fork_result {
-  small_object_storage<sizeof(mixed)> storage{};
-
-public:
-  template<typename T>
-  requires(!std::same_as<T, fork_result>) explicit fork_result(T &&t) noexcept {
-    storage.emplace<std::remove_cvref_t<T>>(std::forward<T>(t));
-  }
-
-  template<typename T>
-  T get_result() noexcept {
-    return *storage.get<T>();
-  }
-};
diff --git a/runtime-light/stdlib/misc.cpp b/runtime-light/stdlib/misc.cpp
index daca639574..a0f342f522 100644
--- a/runtime-light/stdlib/misc.cpp
+++ b/runtime-light/stdlib/misc.cpp
@@ -6,13 +6,13 @@
 
 #include <cstdint>
 
+#include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/component/component.h"
 #include "runtime-light/coroutine/awaitable.h"
 #include "runtime-light/header.h"
 #include "runtime-light/stdlib/superglobals.h"
 #include "runtime-light/streams/streams.h"
 #include "runtime-light/utils/context.h"
-#include "runtime-light/utils/panic.h"
 
 namespace {
 
@@ -60,7 +60,7 @@ task_t<void> finish(int64_t exit_code, bool from_exit) { // TODO: use exit code
   const auto ob_total_buffer = ob_merge_buffers();
   Response &response = component_ctx.response;
   auto &buffer = response.output_buffers[ob_total_buffer];
-  if (co_await write_all_to_stream(standard_stream, buffer.c_str(), buffer.size())) {
+  if ((co_await write_all_to_stream(standard_stream, buffer.c_str(), buffer.size())) != buffer.size()) {
     php_warning("can't write component result to stream %" PRIu64, standard_stream);
   }
   component_ctx.release_all_streams();
diff --git a/runtime-light/stdlib/rpc/rpc-api.cpp b/runtime-light/stdlib/rpc/rpc-api.cpp
index 3fd36bbeae..ea727da862 100644
--- a/runtime-light/stdlib/rpc/rpc-api.cpp
+++ b/runtime-light/stdlib/rpc/rpc-api.cpp
@@ -132,7 +132,7 @@ task_t<RpcQueryInfo> rpc_send_impl(string actor, double timeout, bool ignore_ans
                                                                 : DEFAULT_TIMEOUT_NS};
   // create fork to wait for RPC response. we need to do it even if 'ignore_answer' is 'true' to make sure
   // that the stream will not be closed too early. otherwise, platform may even not send RPC request
-  auto waiter_task{[](int64_t query_id, auto comp_query, std::chrono::nanoseconds timeout, bool collect_responses_extra_info) noexcept -> task_t<fork_result> {
+  auto waiter_task{[](int64_t query_id, auto comp_query, std::chrono::nanoseconds timeout, bool collect_responses_extra_info) noexcept -> task_t<string> {
     auto fetch_task{f$component_client_get_result(std::move(comp_query))};
     const auto response{(co_await wait_with_timeout_t{task_t<string>::awaiter_t{std::addressof(fetch_task)}, timeout}).value_or(string{})};
     // update response extra info if needed
@@ -149,7 +149,7 @@ task_t<RpcQueryInfo> rpc_send_impl(string actor, double timeout, bool ignore_ans
     co_return response;
   }(query_id, std::move(comp_query), timeout_ns, collect_responses_extra_info)};
   // start waiter fork
-  const auto waiter_fork_id{co_await start_fork_t{std::move(waiter_task), start_fork_t::execution::self}};
+  const auto waiter_fork_id{co_await start_fork_t{static_cast<task_t<void>>(std::move(waiter_task)), start_fork_t::execution::self}};
 
   if (ignore_answer) {
     co_return RpcQueryInfo{.id = RPC_IGNORED_ANSWER_QUERY_ID, .request_size = request_size, .timestamp = timestamp};
diff --git a/runtime-light/stdlib/string-functions.cpp b/runtime-light/stdlib/string-functions.cpp
index 3a839a66d1..5039cef93e 100644
--- a/runtime-light/stdlib/string-functions.cpp
+++ b/runtime-light/stdlib/string-functions.cpp
@@ -35,14 +35,14 @@ void f$debug_print_string(const string &s) {
 Optional<int64_t> f$byte_to_int(const string &s) {
   if (s.size() != 1) {
     php_warning("Cannot convert non-byte string to int");
-    return Optional<int64_t>();
+    return {};
   }
   return *s.c_str();
 }
 
 Optional<string> f$int_to_byte(int64_t v) {
   if (v > 127 || v < -128) {
-    php_warning("Cannot convert too big int to byte %ld", v);
+    php_warning("Cannot convert too big int to byte %" PRId64, v);
     return false;
   }
   char c = v;
diff --git a/runtime-light/stdlib/string-functions.h b/runtime-light/stdlib/string-functions.h
index c2ba29b38f..a2264a2fc4 100644
--- a/runtime-light/stdlib/string-functions.h
+++ b/runtime-light/stdlib/string-functions.h
@@ -1,7 +1,6 @@
 #pragma once
 
 #include "runtime-core/runtime-core.h"
-#include <type_traits>
 
 void print(const char *s, size_t s_len);
 
diff --git a/runtime-light/stdlib/timer/timer.h b/runtime-light/stdlib/timer/timer.h
index b771d05fcf..e3c96883c7 100644
--- a/runtime-light/stdlib/timer/timer.h
+++ b/runtime-light/stdlib/timer/timer.h
@@ -19,10 +19,9 @@ task_t<void> f$set_timer(int64_t timeout_ms, T &&on_timer_callback) noexcept {
     php_warning("can't set timer for negative duration %" PRId64 "ms", timeout_ms);
     co_return;
   }
-  const auto fork_f{[](std::chrono::nanoseconds duration, T &&on_timer_callback) -> task_t<fork_result> {
+  const auto fork_f{[](std::chrono::nanoseconds duration, T &&on_timer_callback) -> task_t<void> {
     co_await wait_for_timer_t{duration};
     on_timer_callback();
-    co_return 0;
   }}; // TODO: someone should pop that fork from ForkComponentContext since it will stay there unless we perform f$wait on fork
   const auto duration_ms{std::chrono::milliseconds{static_cast<uint64_t>(timeout_ms)}};
   co_await start_fork_t{fork_f(std::chrono::duration_cast<std::chrono::nanoseconds>(duration_ms), std::forward<T>(on_timer_callback)),
diff --git a/runtime-light/utils/panic.h b/runtime-light/utils/panic.cpp
similarity index 85%
rename from runtime-light/utils/panic.h
rename to runtime-light/utils/panic.cpp
index 88fc2e6b1b..059db31fd8 100644
--- a/runtime-light/utils/panic.h
+++ b/runtime-light/utils/panic.cpp
@@ -2,16 +2,15 @@
 // Copyright (c) 2024 LLC «V Kontakte»
 // Distributed under the GPL v3 License, see LICENSE.notice.txt
 
-#pragma once
-
 #include <csetjmp>
 
-#include "context.h"
+#include "runtime-core/utils/kphp-assert-core.h"
 #include "runtime-light/component/component.h"
 #include "runtime-light/header.h"
+#include "runtime-light/utils/context.h"
 #include "runtime-light/utils/logs.h"
 
-inline void critical_error_handler() {
+void critical_error_handler() {
   constexpr const char *message = "script panic";
   const auto &platform_ctx = *get_platform_context();
   auto &component_ctx = *get_component_context();
diff --git a/runtime-light/utils/php_assert.cpp b/runtime-light/utils/php_assert.cpp
index 0d869406bd..190caca8d3 100644
--- a/runtime-light/utils/php_assert.cpp
+++ b/runtime-light/utils/php_assert.cpp
@@ -2,9 +2,6 @@
 // Copyright (c) 2020 LLC «V Kontakte»
 // Distributed under the GPL v3 License, see LICENSE.notice.txt
 
-#include "runtime-light/utils/php_assert.h"
-
-#include <algorithm>
 #include <csignal>
 #include <cstdarg>
 #include <cstdio>
@@ -16,7 +13,10 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
-#include "runtime-light/utils/panic.h"
+#include "runtime-core/utils/kphp-assert-core.h"
+#include "runtime-light/header.h"
+#include "runtime-light/utils/context.h"
+#include "runtime-light/utils/logs.h"
 
 static void php_warning_impl(bool out_of_memory, int error_type, char const *message, va_list args) {
   (void)out_of_memory;
diff --git a/runtime-light/utils/php_assert.h b/runtime-light/utils/php_assert.h
deleted file mode 100644
index 41d30d4f7b..0000000000
--- a/runtime-light/utils/php_assert.h
+++ /dev/null
@@ -1,13 +0,0 @@
-// Compiler for PHP (aka KPHP)
-// Copyright (c) 2020 LLC «V Kontakte»
-// Distributed under the GPL v3 License, see LICENSE.notice.txt
-
-#pragma once
-
-#include <cstdio>
-#include <unistd.h>
-
-#include "common/wrappers/likely.h"
-#include "common/mixin/not_copyable.h"
-
-#include "runtime-core/utils/kphp-assert-core.h"
diff --git a/runtime-light/utils/utils.cmake b/runtime-light/utils/utils.cmake
index fee0426cd6..f74079da0d 100644
--- a/runtime-light/utils/utils.cmake
+++ b/runtime-light/utils/utils.cmake
@@ -1 +1 @@
-prepend(RUNTIME_UTILS_SRC utils/ php_assert.cpp json-functions.cpp context.cpp)
+prepend(RUNTIME_UTILS_SRC utils/ panic.cpp php_assert.cpp json-functions.cpp context.cpp)
diff --git a/tests/kphp_tester.py b/tests/kphp_tester.py
index 82016c0e9d..abb6253249 100755
--- a/tests/kphp_tester.py
+++ b/tests/kphp_tester.py
@@ -60,7 +60,7 @@ def make_kphp_once_runner(self, use_nocc, cxx_name, k2_bin):
             vkext_dir=os.path.abspath(os.path.join(tester_dir, os.path.pardir, "objs", "vkext")),
             use_nocc=use_nocc,
             cxx_name=cxx_name,
-            k2_bin=k2_bin
+            k2_bin=os.path.abspath(k2_bin)
         )
 
     def set_up_env_for_k2(self, cxx_name="clang++"):
@@ -68,7 +68,6 @@ def set_up_env_for_k2(self, cxx_name="clang++"):
         self.env_vars["KPHP_USER_BINARY_PATH"] = "component.so"
         self.env_vars["KPHP_ENABLE_GLOBAL_VARS_MEMORY_STATS"] = "0"
         self.env_vars["KPHP_PROFILER"] = "0"
-        self.env_vars["KPHP_CXX"] = cxx_name
         self.env_vars["KPHP_K2_COMPONENT_IS_ONESHOT"] = "1"
         self.env_vars["KPHP_FORCE_LINK_RUNTIME"] = "1"
 
diff --git a/tests/phpt/dl/474_flex.php b/tests/phpt/dl/474_flex.php
index e1e26791df..ce61cef0e9 100644
--- a/tests/phpt/dl/474_flex.php
+++ b/tests/phpt/dl/474_flex.php
@@ -1,4 +1,4 @@
-@ok benchmark
+@ok k2_skip benchmark
 <?php
 
 $langs = array (0, 1, 2, 8, 11, 19, 21, 51, 52, 91, 100, 777, 888, 999);
diff --git a/tests/phpt/exceptions/spl/02_builtin_exceptions_1.php b/tests/phpt/exceptions/spl/02_builtin_exceptions_1.php
index 894a6078ab..8456c4bef7 100644
--- a/tests/phpt/exceptions/spl/02_builtin_exceptions_1.php
+++ b/tests/phpt/exceptions/spl/02_builtin_exceptions_1.php
@@ -1,4 +1,4 @@
-@ok php8.2
+@ok k2_skip php8.2
 KPHP_REQUIRE_FUNCTIONS_TYPING=1
 <?php
 
diff --git a/tests/phpt/fork/004_sched_yield_sleep.php b/tests/phpt/fork/004_sched_yield_sleep.php
index fe70066dfa..3c7e6c6bbd 100644
--- a/tests/phpt/fork/004_sched_yield_sleep.php
+++ b/tests/phpt/fork/004_sched_yield_sleep.php
@@ -1,13 +1,13 @@
-@ok non-idempotent k2_skip
+@ok non-idempotent
 <?php
 #ifndef KPHP
 ?>
 1
 2
 3
-waited 1123456789
-waited 1123456790
-waited 1123456791
+waited 0.03
+waited 0.01
+waited 0.02
 <?php
 exit;
 #endif
@@ -15,11 +15,12 @@
 /**
  * @param float $x
  * @param int $y
+ * @return float
  */
 function f($x, $y) {
   sched_yield_sleep($x);
   echo $y . "\n";
-  return null;
+  return $x;
 }
 
 $ids = [];
@@ -28,6 +29,5 @@ function f($x, $y) {
 $ids[] = fork(f(0.02, 2));
 
 foreach ($ids as $id) {
-  wait($id);
-  echo "waited ".(int)$id."\n";
+  echo "waited ". wait($id) ."\n";
 }
diff --git a/tests/phpt/migration_php8/002_string_number_comparison.php b/tests/phpt/migration_php8/002_string_number_comparison.php
index d15457aeca..c3b9abfed3 100644
--- a/tests/phpt/migration_php8/002_string_number_comparison.php
+++ b/tests/phpt/migration_php8/002_string_number_comparison.php
@@ -1,4 +1,4 @@
-@kphp_runtime_should_warn
+@k2_skip kphp_runtime_should_warn
 /Comparison \(operator <\) results in PHP 7 and PHP 8 are different for 0 and "foo" \(PHP7: false, PHP8: true\)/
 /Comparison \(operator <\) results in PHP 7 and PHP 8 are different for 42 and "42foo" \(PHP7: false, PHP8: true\)/
 /Comparison \(operator <\) results in PHP 7 and PHP 8 are different for "100foo" and 42 \(PHP7: false, PHP8: true\)/
diff --git a/tests/phpt/migration_php8/004_string_number_comparison_enable_disable.php b/tests/phpt/migration_php8/004_string_number_comparison_enable_disable.php
index 085613c158..b1d0658c0e 100644
--- a/tests/phpt/migration_php8/004_string_number_comparison_enable_disable.php
+++ b/tests/phpt/migration_php8/004_string_number_comparison_enable_disable.php
@@ -1,4 +1,4 @@
-@kphp_runtime_should_warn
+@k2_skip kphp_runtime_should_warn
 /Comparison \(operator ==\) results in PHP 7 and PHP 8 are different for 0 and "" \(PHP7: true, PHP8: false\)/
 <?php
 
diff --git a/tests/phpt/migration_php8/006_is_numeric.php b/tests/phpt/migration_php8/006_is_numeric.php
index d4305c0195..3c66f5984d 100644
--- a/tests/phpt/migration_php8/006_is_numeric.php
+++ b/tests/phpt/migration_php8/006_is_numeric.php
@@ -1,4 +1,4 @@
-@kphp_runtime_should_warn
+@k2_skip kphp_runtime_should_warn
 /is_numeric\('100 '\) result in PHP 7 and PHP 8 are different \(PHP7: false, PHP8: true\)/
 /is_numeric\('100 \t\t'\) result in PHP 7 and PHP 8 are different \(PHP7: false, PHP8: true\)/
 <?php
diff --git a/tests/phpt/migration_php8/007_string_string_comparison.php b/tests/phpt/migration_php8/007_string_string_comparison.php
index 5555fb4914..bc43e59ecb 100644
--- a/tests/phpt/migration_php8/007_string_string_comparison.php
+++ b/tests/phpt/migration_php8/007_string_string_comparison.php
@@ -1,4 +1,4 @@
-@kphp_runtime_should_warn
+@k2_skip kphp_runtime_should_warn
 /Result of checking that the string is numeric in PHP 7 and PHP 8 are different for '100 ' \(PHP7: false, PHP8: true\)/
 /Result of checking that the string is numeric in PHP 7 and PHP 8 are different for '100 ' \(PHP7: false, PHP8: true\)/
 <?php
diff --git a/tests/phpt/migration_php8/008_string_number_spaceship.php b/tests/phpt/migration_php8/008_string_number_spaceship.php
index b339515f4c..c598cd6861 100644
--- a/tests/phpt/migration_php8/008_string_number_spaceship.php
+++ b/tests/phpt/migration_php8/008_string_number_spaceship.php
@@ -1,4 +1,4 @@
-@kphp_runtime_should_warn
+@k2_skip kphp_runtime_should_warn
 /Comparison \(operator <\) results in PHP 7 and PHP 8 are different for 0 and "foo" \(PHP7: false, PHP8: true\)/
 /Comparison \(operator ==\) results in PHP 7 and PHP 8 are different for 0 and "foo" \(PHP7: true, PHP8: false\)/
 /Comparison \(operator <\) results in PHP 7 and PHP 8 are different for 9 and "42foo" \(PHP7: true, PHP8: false\)/
diff --git a/tests/phpt/migration_php8/009_blank_no_warning.php b/tests/phpt/migration_php8/009_blank_no_warning.php
index 91d802e265..06f74bf384 100644
--- a/tests/phpt/migration_php8/009_blank_no_warning.php
+++ b/tests/phpt/migration_php8/009_blank_no_warning.php
@@ -1,4 +1,4 @@
-@ok kphp_runtime_should_not_warn
+@ok k2_skip kphp_runtime_should_not_warn
 <?php
 
 require_once 'kphp_tester_include.php';
diff --git a/tests/phpt/mixed/non_primitive/008_forks.php b/tests/phpt/mixed/non_primitive/008_forks.php
index 17a3c62325..5a4d1cecc6 100644
--- a/tests/phpt/mixed/non_primitive/008_forks.php
+++ b/tests/phpt/mixed/non_primitive/008_forks.php
@@ -1,4 +1,4 @@
-@ok k2_skip
+@ok
 <?php
 require_once 'kphp_tester_include.php';
 
diff --git a/tests/python/lib/kphp_builder.py b/tests/python/lib/kphp_builder.py
index 0b5a8f9ddc..09c19370d2 100644
--- a/tests/python/lib/kphp_builder.py
+++ b/tests/python/lib/kphp_builder.py
@@ -136,6 +136,7 @@ def compile_with_kphp(self, kphp_env=None):
             env.setdefault("KPHP_CXX", nocc_prepend_to_cxx(self._cxx_name))
             env.update(nocc_make_env())
         else:
+            env.setdefault("KPHP_CXX", self._cxx_name)
             env.setdefault("KPHP_JOBS_COUNT", "2")
 
         # TODO kphp writes error into stdout and info into stderr
diff --git a/tests/python/lib/kphp_run_once.py b/tests/python/lib/kphp_run_once.py
index 9731b10d46..10f1ffb8ef 100644
--- a/tests/python/lib/kphp_run_once.py
+++ b/tests/python/lib/kphp_run_once.py
@@ -153,9 +153,7 @@ def run_with_kphp_and_k2(self, runs_cnt=1, args=[]):
         self._kphp_server_stdout, _kphp_server_stderr = self._wait_proc(k2_runtime_proc)
 
         ignore_stderr = error_can_be_ignored(
-            ignore_patterns=[
-                "^\\[\\d{4}\\-\\d{2}\\-\\d{2}T\\d{2}:\\d{2}:\\d{2}Z INFO {2}main].+$"
-            ],
+            ignore_patterns=[],
             binary_error_text=_kphp_server_stderr)
 
         if not ignore_stderr: