diff --git a/src/nsolid.h b/src/nsolid.h
index 914269d7cf..77f33991ed 100644
--- a/src/nsolid.h
+++ b/src/nsolid.h
@@ -989,9 +989,13 @@ int ThreadMetrics::Update(Cb&& cb, Data&&... data) {
   }
 
   // _1 - ThreadMetrics*
-  UserData* user_data = new UserData(
+  UserData* user_data = new (std::nothrow) UserData(
       std::bind(std::forward<Cb>(cb), _1, std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   user_data_ = user_data;
   proxy_ = thread_metrics_proxy_<UserData>;
   stor_.thread_id = thread_id_;
@@ -1032,8 +1036,13 @@ MetricsStream* MetricsStream::CreateInstance(uint32_t flags,
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
   // _1 - MetricsStream* metrics_stream
   // _2 - const metrics_stream_bucket& bucket
-  UserData* user_data = new UserData(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
     std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
+
+  if (user_data == nullptr) {
+    return nullptr;
+  }
+
   stream->DoSetup(flags,
                   metrics_stream_proxy_<UserData>,
                   internal::delete_proxy_<UserData>,
@@ -1062,8 +1071,13 @@ Tracer* Tracer::CreateInstance(uint32_t flags, Cb&& cb, Data&&... data) {
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
   // _1 - Tracer*
   // _2 - const SpanStor&
-  UserData* user_data = new UserData(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
     std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
+
+  if (user_data == nullptr) {
+    return nullptr;
+  }
+
   tracer->DoSetup(flags,
                   trace_proxy_<UserData>,
                   internal::delete_proxy_<UserData>,
@@ -1092,16 +1106,23 @@ int CpuProfiler::TakeProfile(SharedEnvInst envinst,
 
   // _1 - int status
   // _2 - std::string json
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
+
   int er = get_cpu_profile_(envinst,
                             duration,
-                            user_data.get(),
+                            user_data,
                             cpu_profiler_proxy_<UserData>,
                             internal::delete_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1126,16 +1147,23 @@ int Snapshot::TakeSnapshot(SharedEnvInst envinst,
 
   // _1 - int status
   // _2 - std::string json
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = get_snapshot_(envinst,
                          redacted,
-                         user_data.get(),
+                         user_data,
                          snapshot_proxy_<UserData>,
                          internal::delete_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1151,14 +1179,21 @@ int QueueCallback(Cb&& cb, Data&&... data) {
   using UserData = decltype(std::bind(
         std::forward<Cb>(cb), std::forward<Data>(data)...));
 
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = internal::queue_callback_(
-      user_data.get(),
+      user_data,
       internal::queue_callback_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1168,15 +1203,22 @@ int QueueCallback(uint64_t timeout, Cb&& cb, Data&&... data) {
   using UserData = decltype(std::bind(
         std::forward<Cb>(cb), std::forward<Data>(data)...));
 
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = internal::queue_callback_(
       timeout,
-      user_data.get(),
+      user_data,
       internal::queue_callback_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1191,17 +1233,23 @@ int RunCommand(SharedEnvInst envinst,
   using UserData = decltype(std::bind(
         std::forward<Cb>(cb), _1, std::forward<Data>(data)...));
   // _1 - SharedEnvInst
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = internal::run_command_(
       envinst,
       type,
-      user_data.get(),
+      user_data,
       internal::run_command_proxy_<UserData>);
 
-  if (!er)
-    user_data.release();
+  if (er) {
+    delete user_data;
+  }
+
   return 0;
 }
 
@@ -1223,17 +1271,25 @@ int CustomCommand(SharedEnvInst envinst,
   // _3 - int status
   // _4 - std::pair<bool, std::string> error
   // _5 - std::pair<bool, std::string> value
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, _2, _3, _4, _5, std::forward<Data>(data)...));
+
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = internal::custom_command_(
       envinst,
       req_id,
       command,
       args,
-      user_data.get(),
+      user_data,
       internal::custom_command_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1247,15 +1303,22 @@ int AtExitHook(Cb&& cb, Data&&... data) {
 
   // _1 - bool on_signal
   // _2 - bool profile_stopped
-  std::unique_ptr<UserData> user_data = std::make_unique<UserData>(std::bind(
+  UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
 
+  if (user_data == nullptr) {
+    return UV_ENOMEM;
+  }
+
   int er = internal::at_exit_hook_(
-      user_data.get(),
+      user_data,
       internal::at_exit_hook_proxy_<UserData>,
       internal::delete_proxy_<UserData>);
-  if (!er)
-    user_data.release();
+
+  if (er) {
+    delete user_data;
+  }
+
   return er;
 }
 
@@ -1271,6 +1334,7 @@ int OnBlockedLoopHook(uint64_t threshold, Cb&& cb, Data&&... data) {
   // _2 - std::string info
   UserData* user_data = new (std::nothrow) UserData(std::bind(
         std::forward<Cb>(cb), _1, _2, std::forward<Data>(data)...));
+
   if (user_data == nullptr) {
     return UV_ENOMEM;
   }