diff --git a/CMakeLists.txt b/CMakeLists.txt
index 81fe1e3..57629e7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 ###
-### Copyright 2015-2024 Oliver Giles
+### Copyright 2015-2026 Oliver Giles
 ###
 ### This file is part of Laminar
 ###
@@ -16,7 +16,7 @@
 ### You should have received a copy of the GNU General Public License
 ### along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ###
-cmake_minimum_required(VERSION 3.6)
+cmake_minimum_required(VERSION 3.18)
 project(laminar)
 
 if (${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
@@ -57,7 +57,7 @@ if (LLVM_LINKER_IS_LLD)
 endif()
 
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter -Wno-sign-compare")
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Werror -DDEBUG")
@@ -160,8 +160,8 @@ include_directories(${Threads_INCLUDE_DIRS})
 
 ## Server
 add_executable(laminard ${LAMINARD_CORE_SOURCES} src/main.cpp ${COMPRESSED_BINS})
-target_link_libraries(laminard CapnProto::capnp-rpc CapnProto::capnp CapnProto::kj-http CapnProto::kj-async 
-                               CapnProto::kj Threads::Threads SQLite::SQLite3 ZLIB::ZLIB)
+target_link_libraries(laminard CapnProto::capnp-rpc CapnProto::capnp CapnProto::kj-http CapnProto::kj-async
+                               CapnProto::kj Threads::Threads SQLite3::SQLite3 ZLIB::ZLIB)
 
 if (${CMAKE_SYSTEM_NAME} STREQUAL "FreeBSD")
     pkg_check_modules(INOTIFY REQUIRED libinotify)
@@ -191,7 +191,8 @@ if(BUILD_TESTS)
     find_package(GTest REQUIRED)
     include_directories(${GTEST_INCLUDE_DIRS} src)
     add_executable(laminar-tests ${LAMINARD_CORE_SOURCES} ${COMPRESSED_BINS} test/main.cpp test/laminar-functional.cpp test/unit-conf.cpp test/unit-database.cpp)
-    target_link_libraries(laminar-tests ${GTEST_LIBRARIES} capnp-rpc capnp kj-http kj-async kj pthread sqlite3 z)
+    target_link_libraries(laminar-tests ${GTEST_LIBRARIES} CapnProto::capnp-rpc CapnProto::capnp CapnProto::kj-http CapnProto::kj-async CapnProto::kj
+                                        Threads::Threads SQLite3::SQLite3 ZLIB::ZLIB)
 endif()
 
 set(BASH_COMPLETIONS_DIR /usr/share/bash-completion/completions CACHE PATH "Path to bash completions directory")
diff --git a/README.md b/README.md
index 685a0e6..1b1a078 100644
--- a/README.md
+++ b/README.md
@@ -12,7 +12,7 @@ See [the website](https://laminar.ohwg.net) and the [documentation](https://lami
 
 First install development packages for `capnproto (version 0.7.0 or newer)`, `rapidjson`, `sqlite` and `boost` (for the header-only `multi_index_container` library) from your distribution's repository or other source.
 
-On Debian Bookworm, this can be done with:
+On Debian 13 (Trixie), this can be done with:
 
 ```bash
 sudo apt install capnproto cmake g++ libboost-dev libcapnp-dev libsqlite3-dev \
diff --git a/src/conf.h b/src/conf.h
index bc355a7..7e5c63e 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_CONF_H_
-#define LAMINAR_CONF_H_
+#pragma once
 
 #include <string>
 #include <unordered_map>
@@ -41,5 +40,3 @@ int StringMap::convert(std::string e);
 // beginning with '#'
 StringMap parseConfFile(const char* path);
 
-
-#endif // LAMINAR_CONF_H_
diff --git a/src/context.h b/src/context.h
index 7ae1b0b..53cc841 100644
--- a/src/context.h
+++ b/src/context.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2020 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_CONTEXT_H_
-#define LAMINAR_CONTEXT_H_
+#pragma once
 
 #include <string>
 #include <set>
@@ -36,5 +35,3 @@ public:
     std::set<std::string> jobPatterns;
 };
 
-
-#endif // LAMINAR_CONTEXT_H_
diff --git a/src/database.h b/src/database.h
index 56ded6a..d84a8be 100644
--- a/src/database.h
+++ b/src/database.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2018 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_DATABASE_H_
-#define LAMINAR_DATABASE_H_
+#pragma once
 
 #include <string>
 #include <functional>
@@ -157,4 +156,3 @@ template<> long Database::Statement::fetchColumn(int col);
 template<> ulong Database::Statement::fetchColumn(int col);
 template<> double Database::Statement::fetchColumn(int col);
 
-#endif // LAMINAR_DATABASE_H_
diff --git a/src/http.h b/src/http.h
index fc8db5a..df00c14 100644
--- a/src/http.h
+++ b/src/http.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2019-2020 Oliver Giles
+/// Copyright 2019-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_HTTP_H_
-#define LAMINAR_HTTP_H_
+#pragma once
 
 #include <kj/memory.h>
 #include <kj/compat/http.h>
@@ -66,4 +65,3 @@ private:
     kj::HttpHeaderId ACCEPT;
 };
 
-#endif //LAMINAR_HTTP_H_
diff --git a/src/laminar.h b/src/laminar.h
index a983c09..e369c56 100644
--- a/src/laminar.h
+++ b/src/laminar.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2022 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,14 +16,14 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_LAMINAR_H_
-#define LAMINAR_LAMINAR_H_
+#pragma once
 
 #include "run.h"
 #include "monitorscope.h"
 #include "context.h"
 #include "database.h"
 
+#include <list>
 #include <unordered_map>
 #include <kj/filesystem.h>
 #include <kj/async-io.h>
@@ -134,4 +134,3 @@ private:
     kj::Own<Rpc> rpc;
 };
 
-#endif // LAMINAR_LAMINAR_H_
diff --git a/src/leader.h b/src/leader.h
index 2da6095..1ba3448 100644
--- a/src/leader.h
+++ b/src/leader.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2019 Oliver Giles
+/// Copyright 2019-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_LEADER_H_
-#define LAMINAR_LEADER_H_
+#pragma once
 
 // Main function for the leader process which is responsible for
 // executing all the scripts which make up a Run. Separating this
@@ -33,4 +32,3 @@
 
 int leader_main(void);
 
-#endif // LAMINAR_LEADER_H_
diff --git a/src/log.h b/src/log.h
index a0ccff4..c3f546c 100644
--- a/src/log.h
+++ b/src/log.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2020 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_LOG_H_
-#define LAMINAR_LOG_H_
+#pragma once
 
 #include <kj/debug.h>
 #include <utility>
@@ -69,5 +68,3 @@ namespace _ {
 
 const char* laminar_version();
 
-#endif // LAMINAR_LOG_H_
-
diff --git a/src/monitorscope.h b/src/monitorscope.h
index 987eafe..c46f359 100644
--- a/src/monitorscope.h
+++ b/src/monitorscope.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2019 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_MONITORSCOPE_H_
-#define LAMINAR_MONITORSCOPE_H_
+#pragma once
 
 #include <string>
 
@@ -59,5 +58,3 @@ struct MonitorScope {
     bool order_desc;
 };
 
-#endif // LAMINAR_MONITORSCOPE_H_
-
diff --git a/src/resources.h b/src/resources.h
index 1f8f951..edf1923 100644
--- a/src/resources.h
+++ b/src/resources.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2019 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_RESOURCES_H_
-#define LAMINAR_RESOURCES_H_
+#pragma once
 
 #include <unordered_map>
 #include <utility>
@@ -47,4 +46,3 @@ private:
     std::string index_html;
 };
 
-#endif // LAMINAR_RESOURCES_H_
diff --git a/src/rpc.h b/src/rpc.h
index 0f55d2c..ff60d8d 100644
--- a/src/rpc.h
+++ b/src/rpc.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2019-2020 Oliver Giles
+/// Copyright 2019-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_RPC_H_
-#define LAMINAR_RPC_H_
+#pragma once
 
 #include <capnp/ez-rpc.h>
 #include <capnp/rpc-twoparty.h>
@@ -33,4 +32,3 @@ public:
     capnp::Capability::Client rpcInterface;
 };
 
-#endif //LAMINAR_RPC_H_
diff --git a/src/run.h b/src/run.h
index 7e9e67f..d1a0d28 100644
--- a/src/run.h
+++ b/src/run.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2018 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,14 +16,10 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_RUN_H_
-#define LAMINAR_RUN_H_
+#pragma once
 
 #include <string>
-#include <queue>
-#include <list>
 #include <functional>
-#include <ostream>
 #include <unordered_map>
 #include <memory>
 #include <kj/async.h>
@@ -109,6 +105,7 @@ private:
 // be executing thousands of builds at the same time
 #include <boost/multi_index_container.hpp>
 #include <boost/multi_index/hashed_index.hpp>
+#include <boost/multi_index/indexed_by.hpp>
 #include <boost/multi_index/member.hpp>
 #include <boost/multi_index/composite_key.hpp>
 #include <boost/multi_index/global_fun.hpp>
@@ -125,7 +122,7 @@ struct _run_same {
 };
 
 // A single Run can be fetched by...
-struct _run_index : bmi::indexed_by<
+typedef bmi::indexed_by<
         bmi::hashed_unique<bmi::composite_key<
             std::shared_ptr<Run>,
         // a combination of their job name and build number
@@ -138,8 +135,7 @@ struct _run_index : bmi::indexed_by<
         bmi::ordered_non_unique<bmi::member<Run, time_t, &Run::startedAt>>,
         // or by their job name
         bmi::ordered_non_unique<bmi::member<Run, std::string, &Run::name>>
-    >
-{};
+    > _run_index;
 
 struct RunSet: public boost::multi_index_container<
     std::shared_ptr<Run>,
@@ -158,4 +154,3 @@ struct RunSet: public boost::multi_index_container<
     typename bmi::nth_index<RunSet, 3>::type const& byJobName() const { return get<3>(); }
 };
 
-#endif // LAMINAR_RUN_H_
diff --git a/src/server.cpp b/src/server.cpp
index 06cbbba..1fd5b22 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2021 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -26,7 +26,6 @@
 #include <kj/async-unix.h>
 #include <kj/threadlocal.h>
 
-#include <signal.h>
 #include <sys/eventfd.h>
 #include <sys/stat.h>
 #include <sys/inotify.h>
@@ -149,11 +148,10 @@ void Server::listenHttp(Http &http, kj::StringPtr httpBindAddress)
 
 kj::Promise<void> Server::acceptRpcClient(Rpc& rpc, kj::Own<kj::ConnectionReceiver>&& listener) {
     kj::ConnectionReceiver& cr = *listener.get();
-    return cr.accept().then(kj::mvCapture(kj::mv(listener),
-        [this, &rpc](kj::Own<kj::ConnectionReceiver>&& listener, kj::Own<kj::AsyncIoStream>&& connection) {
+    return cr.accept().then([this, &rpc, l = kj::mv(listener)](kj::Own<kj::AsyncIoStream>&& connection) mutable {
             addTask(rpc.accept(kj::mv(connection)));
-            return acceptRpcClient(rpc, kj::mv(listener));
-        }));
+            return acceptRpcClient(rpc, kj::mv(l));
+        });
 }
 
 // returns a promise which will read a chunk of data from the file descriptor
diff --git a/src/server.h b/src/server.h
index d0433da..66d5f1c 100644
--- a/src/server.h
+++ b/src/server.h
@@ -1,5 +1,5 @@
 ///
-/// Copyright 2015-2020 Oliver Giles
+/// Copyright 2015-2026 Oliver Giles
 ///
 /// This file is part of Laminar
 ///
@@ -16,8 +16,7 @@
 /// You should have received a copy of the GNU General Public License
 /// along with Laminar.  If not, see <http://www.gnu.org/licenses/>
 ///
-#ifndef LAMINAR_SERVER_H_
-#define LAMINAR_SERVER_H_
+#pragma once
 
 #include <kj/async-io.h>
 #include <kj/compat/http.h>
@@ -72,4 +71,3 @@ private:
     kj::Maybe<kj::Promise<void>> reapWatch;
 };
 
-#endif // LAMINAR_SERVER_H_
diff --git a/test/eventsource.h b/test/eventsource.h
index c124381..1c66751 100644
--- a/test/eventsource.h
+++ b/test/eventsource.h
@@ -52,7 +52,7 @@ private:
     std::vector<rapidjson::Document> receivedMessages;
 
     kj::Promise<void> waitForMessages(kj::AsyncInputStream* stream, ulong offset) {
-        return stream->read(buffer.asPtr().begin() + offset, 1, BUFFER_SIZE).then([=](size_t s) {
+        return stream->read(buffer.asPtr().begin() + offset, 1, BUFFER_SIZE).then([=, this](size_t s) {
             ulong end = offset + s;
             buffer.asPtr().begin()[end] = '\0';
             if(strcmp(&buffer.asPtr().begin()[end - 2], "\n\n") == 0) {