diff --git a/src/event/EpollBackend.hxx b/src/event/EpollBackend.hxx
index 9ea024a0b..e623591f0 100644
--- a/src/event/EpollBackend.hxx
+++ b/src/event/EpollBackend.hxx
@@ -20,7 +20,6 @@
 #ifndef EVENT_EPOLL_BACKEND_HXX
 #define EVENT_EPOLL_BACKEND_HXX
 
-#include "util/Compiler.h"
 #include "system/EpollFD.hxx"
 
 #include <array>
diff --git a/src/event/Loop.hxx b/src/event/Loop.hxx
index 5a936d03f..664ec1c77 100644
--- a/src/event/Loop.hxx
+++ b/src/event/Loop.hxx
@@ -25,7 +25,6 @@
 #include "SocketEvent.hxx"
 #include "event/Features.h"
 #include "time/ClockCache.hxx"
-#include "util/Compiler.h"
 #include "util/IntrusiveList.hxx"
 
 #ifdef HAVE_THREADED_EVENT_LOOP
@@ -183,7 +182,7 @@ public:
 	 * iteration, because it is assumed that the event loop runs
 	 * for a negligible duration.
 	 */
-	gcc_pure
+	[[gnu::pure]]
 	const auto &SteadyNow() const noexcept {
 #ifdef HAVE_THREADED_EVENT_LOOP
 		assert(IsInside());
@@ -193,7 +192,7 @@ public:
 	}
 
 #ifdef HAVE_URING
-	gcc_pure
+	[[gnu::pure]]
 	Uring::Queue *GetUring() noexcept;
 #endif
 
@@ -298,7 +297,7 @@ public:
 	/**
 	 * Are we currently running inside this EventLoop's thread?
 	 */
-	gcc_pure
+	[[gnu::pure]]
 	bool IsInside() const noexcept {
 #ifdef HAVE_THREADED_EVENT_LOOP
 		return thread.IsInside();
diff --git a/src/event/ServerSocket.cxx b/src/event/ServerSocket.cxx
index 3b907efa5..778a2b8ce 100644
--- a/src/event/ServerSocket.cxx
+++ b/src/event/ServerSocket.cxx
@@ -100,7 +100,7 @@ public:
 		event.Close();
 	}
 
-	[[nodiscard]] gcc_pure
+	[[nodiscard]] [[gnu::pure]]
 	std::string ToString() const noexcept {
 		return ::ToString(address);
 	}
@@ -328,7 +328,7 @@ ServerSocket::AddPortIPv6(unsigned port) noexcept
 /**
  * Is IPv6 supported by the kernel?
  */
-gcc_pure
+[[gnu::pure]]
 static bool
 SupportsIPv6() noexcept
 {