diff --git a/src/event/MultiSocketMonitor.cxx b/src/event/MultiSocketMonitor.cxx
index f747fd0f9..98d57332c 100644
--- a/src/event/MultiSocketMonitor.cxx
+++ b/src/event/MultiSocketMonitor.cxx
@@ -42,6 +42,18 @@ MultiSocketMonitor::Reset() noexcept
 	ready = refresh = false;
 }
 
+bool
+MultiSocketMonitor::AddSocket(SocketDescriptor fd, unsigned events) noexcept
+{
+	fds.emplace_front(*this, fd);
+	bool success = fds.front().Schedule(events);
+	if (!success) {
+		fds.pop_front();
+	}
+
+	return success;
+}
+
 void
 MultiSocketMonitor::ClearSocketList() noexcept
 {
diff --git a/src/event/MultiSocketMonitor.hxx b/src/event/MultiSocketMonitor.hxx
index c4bad8ac0..c1d363a29 100644
--- a/src/event/MultiSocketMonitor.hxx
+++ b/src/event/MultiSocketMonitor.hxx
@@ -145,15 +145,7 @@ public:
 	 *
 	 * May only be called from PrepareSockets().
 	 */
-	bool AddSocket(SocketDescriptor fd, unsigned events) noexcept {
-		fds.emplace_front(*this, fd);
-		bool success = fds.front().Schedule(events);
-		if (!success) {
-			fds.pop_front();
-		}
-
-		return success;
-	}
+	bool AddSocket(SocketDescriptor fd, unsigned events) noexcept;
 
 	/**
 	 * Remove all sockets.