diff --git a/nixd/include/nixd/Eval/AttrSetClient.h b/nixd/include/nixd/Eval/AttrSetClient.h
index d1edbc794..11931d9b4 100644
--- a/nixd/include/nixd/Eval/AttrSetClient.h
+++ b/nixd/include/nixd/Eval/AttrSetClient.h
@@ -32,6 +32,8 @@ class AttrSetClient : public lspserver::LSPServer {
                              lspserver::Callback<OptionCompleteResponse> Reply)>
       OptionComplete;
 
+  llvm::unique_function<void(std::nullptr_t)> Exit;
+
 public:
   AttrSetClient(std::unique_ptr<lspserver::InboundPort> In,
                 std::unique_ptr<lspserver::OutboundPort> Out);
@@ -63,6 +65,8 @@ class AttrSetClient : public lspserver::LSPServer {
     OptionComplete(Params, std::move(Reply));
   }
 
+  void exit() { Exit(nullptr); }
+
   /// Get executable path for launching the server.
   /// \returns null terminated string.
   static const char *getExe();
@@ -78,6 +82,7 @@ class AttrSetClientProc {
   /// \returns nullptr if it has been dead.
   AttrSetClient *client();
   ~AttrSetClientProc() {
+    Client.exit();
     Client.closeInbound();
     Input.join();
   }
diff --git a/nixd/include/nixd/Support/AutoHUPPID.h b/nixd/include/nixd/Support/AutoHUPPID.h
deleted file mode 100644
index 0c1a20126..000000000
--- a/nixd/include/nixd/Support/AutoHUPPID.h
+++ /dev/null
@@ -1,17 +0,0 @@
-#include <sched.h>
-#include <signal.h> // NOLINT(modernize-deprecated-headers)
-
-namespace nixd::util {
-
-class AutoHUPPID {
-  pid_t Pid;
-
-public:
-  AutoHUPPID(pid_t Pid) noexcept : Pid(Pid) {}
-
-  ~AutoHUPPID() { kill(Pid, SIGKILL); }
-
-  operator pid_t() const { return Pid; }
-};
-
-} // namespace nixd::util
diff --git a/nixd/include/nixd/Support/PipedProc.h b/nixd/include/nixd/Support/PipedProc.h
index ab61bde52..123be7984 100644
--- a/nixd/include/nixd/Support/PipedProc.h
+++ b/nixd/include/nixd/Support/PipedProc.h
@@ -1,12 +1,13 @@
 #pragma once
 
 #include "AutoCloseFD.h"
-#include "AutoHUPPID.h"
+
+#include <sys/types.h>
 
 namespace nixd::util {
 
 struct PipedProc {
-  AutoHUPPID PID;
+  pid_t PID;
 
   // Piped descriptors
   AutoCloseFD Stdin;
diff --git a/nixd/lib/Eval/AttrSetClient.cpp b/nixd/lib/Eval/AttrSetClient.cpp
index 3c36293fa..cf35e6162 100644
--- a/nixd/lib/Eval/AttrSetClient.cpp
+++ b/nixd/lib/Eval/AttrSetClient.cpp
@@ -2,6 +2,8 @@
 
 #include "nixd/Eval/AttrSetClient.h"
 
+#include <signal.h> // NOLINT(modernize-deprecated-headers)
+
 using namespace nixd;
 using namespace lspserver;
 
@@ -18,6 +20,7 @@ AttrSetClient::AttrSetClient(std::unique_ptr<lspserver::InboundPort> In,
       mkOutMethod<AttrPathInfoParams, OptionInfoResponse>("attrset/optionInfo");
   OptionComplete = mkOutMethod<AttrPathCompleteParams, OptionCompleteResponse>(
       "attrset/optionComplete");
+  Exit = mkOutNotifiction<std::nullptr_t>("exit");
 }
 
 const char *AttrSetClient::getExe() {