diff --git a/.sai.json b/.sai.json
index 76da2b229..ac00c3aca 100644
--- a/.sai.json
+++ b/.sai.json
@@ -195,6 +195,10 @@
 		"libglib": {
 			"cmake":	"-DLWS_WITH_GLIB=ON"
 		},
+		"sdevent": {
+			"cmake":	"-DLWS_WITH_SDEVENT=ON",
+			"platforms":	"none, linux-fedora-32/x86_64-amd/gcc"
+		},
 		"ipv6":	{
 			"cmake":	"-DLWS_IPV6=ON",
 			"platforms":	"windows-10/x86_64-amd/mingw64, windows-10/x86_64-amd/msvc"
diff --git a/CMakeLists-implied-options.txt b/CMakeLists-implied-options.txt
index eb4f306b5..3c52fb6d6 100644
--- a/CMakeLists-implied-options.txt
+++ b/CMakeLists-implied-options.txt
@@ -118,7 +118,8 @@ endif()
 if (LWS_WITH_LIBEV OR
     LWS_WITH_LIBUV OR
     LWS_WITH_LIBEVENT OR
-    LWS_WITH_GLIB)
+    LWS_WITH_GLIB OR
+    LWS_WITH_SDEVENT)
 	set(LWS_WITH_EVENT_LIBS 1)
 else()
 	unset(LWS_WITH_EVENT_LIBS)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index cfcc1f049..cf418e907 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -171,6 +171,7 @@ option(LWS_WITH_LIBEV "Compile with support for libev" OFF)
 option(LWS_WITH_LIBUV "Compile with support for libuv" OFF)
 option(LWS_WITH_LIBEVENT "Compile with support for libevent" OFF)
 option(LWS_WITH_GLIB "Compile with support for glib event loop" OFF)
+option(LWS_WITH_SDEVENT "Compile with support for sd-event loop" OFF)
 
 if (UNIX)
 # since v4.1, on unix platforms default is build any event libs as runtime plugins
diff --git a/cmake/lws_config.h.in b/cmake/lws_config.h.in
index e34e80139..329218cae 100644
--- a/cmake/lws_config.h.in
+++ b/cmake/lws_config.h.in
@@ -152,6 +152,7 @@
 #cmakedefine LWS_WITH_LIBEV
 #cmakedefine LWS_WITH_LIBEVENT
 #cmakedefine LWS_WITH_LIBUV
+#cmakedefine LWS_WITH_SDEVENT
 #cmakedefine LWS_WITH_LWSAC
 #cmakedefine LWS_LOGS_TIMESTAMP
 #cmakedefine LWS_WITH_MBEDTLS
diff --git a/include/libwebsockets/lws-context-vhost.h b/include/libwebsockets/lws-context-vhost.h
index 796cc476f..2a7bdbe59 100644
--- a/include/libwebsockets/lws-context-vhost.h
+++ b/include/libwebsockets/lws-context-vhost.h
@@ -233,6 +233,10 @@
 #define LWS_SERVER_OPTION_SS_PROXY				 (1ll << 36)
 	/**< (VH) We are being a SS Proxy listen socket for the vhost */
 
+#define LWS_SERVER_OPTION_SDEVENT			 	 (1ll << 37)
+	/**< (CTX) Use sd-event loop */
+
+
 	/****** add new things just above ---^ ******/
 
 
diff --git a/lib/core/context.c b/lib/core/context.c
index fe66b9879..d11246ef1 100644
--- a/lib/core/context.c
+++ b/lib/core/context.c
@@ -369,6 +369,7 @@ static const struct lws_evlib_map {
 	{ LWS_SERVER_OPTION_LIBEVENT, "evlib_event" },
 	{ LWS_SERVER_OPTION_GLIB,     "evlib_glib" },
 	{ LWS_SERVER_OPTION_LIBEV,    "evlib_ev" },
+	{ LWS_SERVER_OPTION_SDEVENT,  "evlib_sd" },
 };
 static const char * const dlist[] = {
 	".",				/* Priority 1: plugins in cwd */
@@ -598,6 +599,13 @@ lws_create_context(const struct lws_context_creation_info *info)
 	}
 #endif
 
+#if defined(LWS_WITH_SDEVENT)
+    if (lws_check_opt(info->options, LWS_SERVER_OPTION_SDEVENT)) {
+        extern const lws_plugin_evlib_t evlib_sd;
+        plev = &evlib_sd;
+    }
+#endif
+
 #endif /* with event libs */
 
 #endif /* not with ev plugins */
diff --git a/lib/event-libs/CMakeLists.txt b/lib/event-libs/CMakeLists.txt
index 3bb647652..b0226c281 100644
--- a/lib/event-libs/CMakeLists.txt
+++ b/lib/event-libs/CMakeLists.txt
@@ -92,6 +92,10 @@ if (LWS_WITH_LIBEV)
 	set(LWS_HAVE_EVBACKEND_IOURING ${LWS_HAVE_EVBACKEND_IOURING} PARENT_SCOPE)
 endif()
 
+if (LWS_WITH_SDEVENT)
+	add_subdir_include_directories(sdevent)
+endif()
+
 
 
 #
diff --git a/lib/event-libs/README.md b/lib/event-libs/README.md
index 69ea7633f..5d49bec1f 100644
--- a/lib/event-libs/README.md
+++ b/lib/event-libs/README.md
@@ -8,7 +8,7 @@ and native WSA on windows.
 To get access to epoll() or other platform specific better poll waits, or to
 integrate with existing applications already using a specific event loop, it can
 be desirable for lws to use another external event library, like libuv, glib,
-libevent or libev.
+libevent, libev, or sdevent.
 
 Lws supports wholesale replacement of its wait selectable at runtime, either by
 building support for one or more event lib into the libwebsockets library, or by
diff --git a/lib/event-libs/sdevent/CMakeLists.txt b/lib/event-libs/sdevent/CMakeLists.txt
new file mode 100644
index 000000000..c4222d388
--- /dev/null
+++ b/lib/event-libs/sdevent/CMakeLists.txt
@@ -0,0 +1,44 @@
+# The strategy is to only export to PARENT_SCOPE
+#
+#  - changes to LIB_LIST
+#  - includes via include_directories
+#
+# and keep everything else private
+
+include_directories(.)
+
+# configure or find systemd library
+set(LIB_SYSTEMD_LIBRARIES CACHE PATH "Path to the libsystemd library")
+if ("${LWS_SYSTEMD_LIBRARIES}" STREQUAL "")
+    if (NOT LIB_SYSTEMD_FOUND)
+        find_path(LIBSYSTEMD_INCLUDE_DIRS NAMES systemd/sd-event.h)
+        find_library(LIBSYSTEMD_LIBRARIES NAMES systemd)
+    endif()
+else()
+    set(LIBSYSTEMD_LIBRARIES ${LWS_SYSTEMD_LIBRARIES})
+    set(LIBSYSTEMD_INCLUDE_DIRS ${LWS_LIBSYSTEMD_INCLUDE_DIRS})
+endif()
+message("libsystemd include dir: ${LIBSYSTEMD_INCLUDE_DIRS}")
+message("libsystemd libraries: ${LIBSYSTEMD_LIBRARIES}")
+
+if (LWS_WITH_EVLIB_PLUGINS)
+
+    create_evlib_plugin(
+            evlib_sd
+            sdevent.c
+            private-lib-event-libs-sdevent.h
+            ${LIBSYSTEMD_LIBRARIES}
+    )
+
+else()
+
+    list(APPEND LIB_LIST ${LIBSYSTEMD_LIBRARIES})
+    list(APPEND SOURCES event-libs/sdevent/sdevent.c)
+
+endif()
+
+#
+# Keep explicit parent scope exports at end
+#
+
+exports_to_parent_scope()
diff --git a/lib/event-libs/sdevent/private-lib-event-libs-sdevent.h b/lib/event-libs/sdevent/private-lib-event-libs-sdevent.h
new file mode 100644
index 000000000..b530d7052
--- /dev/null
+++ b/lib/event-libs/sdevent/private-lib-event-libs-sdevent.h
@@ -0,0 +1,3 @@
+#include <private-lib-core.h>
+
+extern const struct lws_event_loop_ops event_loop_ops_sdevent;
diff --git a/lib/event-libs/sdevent/sdevent.c b/lib/event-libs/sdevent/sdevent.c
new file mode 100644
index 000000000..3f49fe01a
--- /dev/null
+++ b/lib/event-libs/sdevent/sdevent.c
@@ -0,0 +1,431 @@
+#include <systemd/sd-event.h>
+
+#include <private-lib-core.h>
+#include "private-lib-event-libs-sdevent.h"
+
+#define pt_to_priv_sd(_pt) ((struct lws_pt_eventlibs_sdevent *)(_pt)->evlib_pt)
+#define wsi_to_priv_sd(_w) ((struct lws_wsi_watcher_sdevent *)(_w)->evlib_wsi)
+
+struct lws_pt_eventlibs_sdevent {
+	struct lws_context_per_thread *pt;
+	struct sd_event *io_loop;
+	struct sd_event_source *sultimer;
+	struct sd_event_source *idletimer;
+};
+
+struct lws_wsi_watcher_sdevent {
+	struct sd_event_source *source;
+	uint32_t events;
+};
+
+static int
+sultimer_handler(sd_event_source *s, uint64_t usec, void *userdata)
+{
+	struct lws_context_per_thread *pt = (struct lws_context_per_thread *)userdata;
+
+	lws_usec_t us;
+
+	lws_context_lock(pt->context, __func__);
+	lws_pt_lock(pt, __func__);
+
+	us = __lws_sul_service_ripe(pt->pt_sul_owner, LWS_COUNT_PT_SUL_OWNERS,
+				    lws_now_usecs());
+	if (us) {
+		uint64_t at;
+
+		sd_event_now(sd_event_source_get_event(s), CLOCK_MONOTONIC, &at);
+		at += (uint64_t)us;
+		sd_event_source_set_time(pt_to_priv_sd(pt)->sultimer, at);
+		sd_event_source_set_enabled(pt_to_priv_sd(pt)->sultimer,
+					    SD_EVENT_ONESHOT);
+	}
+
+	lws_pt_unlock(pt);
+	lws_context_unlock(pt->context);
+
+	return 0;
+}
+
+static int
+idle_handler(sd_event_source *s, uint64_t usec, void *userdata)
+{
+	struct lws_context_per_thread *pt = (struct lws_context_per_thread *)userdata;
+
+	lws_usec_t us;
+
+	lws_service_do_ripe_rxflow(pt);
+
+	lws_context_lock(pt->context, __func__);
+	lws_pt_lock(pt, __func__);
+
+	/*
+	 * is there anybody with pending stuff that needs service forcing?
+	 */
+	 if (!lws_service_adjust_timeout(pt->context, 1, pt->tid))
+		 /* -1 timeout means just do forced service */
+		 _lws_plat_service_forced_tsi(pt->context, pt->tid);
+
+	 /* account for sultimer */
+
+	 us = __lws_sul_service_ripe(pt->pt_sul_owner, LWS_COUNT_PT_SUL_OWNERS,
+				     lws_now_usecs());
+
+	 if (us) {
+		 uint64_t at;
+
+		 sd_event_now(sd_event_source_get_event(s), CLOCK_MONOTONIC, &at);
+		 at += (uint64_t)us;
+		 sd_event_source_set_time(pt_to_priv_sd(pt)->sultimer, at);
+		 sd_event_source_set_enabled(pt_to_priv_sd(pt)->sultimer,
+					     SD_EVENT_ONESHOT);
+	 }
+
+	 sd_event_source_set_enabled(pt_to_priv_sd(pt)->idletimer, SD_EVENT_OFF);
+
+	 lws_pt_unlock(pt);
+	 lws_context_unlock(pt->context);
+
+	 return 0;
+}
+
+static int
+sock_accept_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata)
+{
+	struct lws *wsi = (struct lws *)userdata;
+	struct lws_context *context = wsi->a.context;
+	struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
+	struct sd_event_source *idletimer, *watcher;
+	struct lws_pollfd eventfd;
+
+	lws_context_lock(pt->context, __func__);
+	lws_pt_lock(pt, __func__);
+
+	if (pt->is_destroyed)
+		goto bail;
+
+	eventfd.fd = fd;
+	eventfd.events = 0;
+	eventfd.revents = 0;
+
+	if (revents & EPOLLIN) {
+		eventfd.events |= LWS_POLLIN;
+		eventfd.revents |= LWS_POLLIN;
+	}
+
+	if (revents & EPOLLOUT) {
+		eventfd.events |= LWS_POLLOUT;
+		eventfd.revents |= LWS_POLLOUT;
+	}
+
+	lws_pt_unlock(pt);
+	lws_context_unlock(pt->context);
+
+	lws_service_fd_tsi(context, &eventfd, wsi->tsi);
+
+	if (pt->destroy_self) {
+		lws_context_destroy(pt->context);
+		return -1;
+	}
+
+	/* fire idle handler */
+	idletimer = pt_to_priv_sd(pt)->idletimer;
+	if (idletimer) {
+		sd_event_source_set_time(idletimer, (uint64_t) 0);
+		sd_event_source_set_enabled(idletimer, SD_EVENT_ON);
+	}
+
+	/*
+	 * allow further events
+	 *
+	 * Note:
+	 * do not move the assignment up, lws_service_fd_tsi may invalidate it!
+	 */
+	watcher = wsi_to_priv_sd(wsi)->source;
+	if (watcher)
+		sd_event_source_set_enabled(watcher, SD_EVENT_ONESHOT);
+
+	return 0;
+
+bail:
+	lws_pt_unlock(pt);
+	lws_context_unlock(pt->context);
+
+	return -1;
+}
+
+static void
+io_sd(struct lws *wsi, unsigned int flags)
+{
+	struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
+
+	/*
+	 * Only manipulate if there is an event source, and if
+	 * the pt is still alive
+	 */
+	if (!pt_to_priv_sd(pt)->io_loop ||
+	    !wsi_to_priv_sd(wsi)->source ||
+	    pt->is_destroyed)
+		return;
+
+	// assert that the requested flags do not contain anything unexpected
+	if (!((flags & (LWS_EV_START | LWS_EV_STOP)) &&
+	    (flags & (LWS_EV_READ | LWS_EV_WRITE)))) {
+		lwsl_err("%s: assert: flags %d", __func__, flags);
+		assert(0);
+	}
+
+	// we are overdoing a bit here, so it resembles the structure in libuv.c
+	if (flags & LWS_EV_START) {
+		if (flags & LWS_EV_WRITE)
+			wsi_to_priv_sd(wsi)->events |= EPOLLOUT;
+
+		if (flags & LWS_EV_READ)
+			wsi_to_priv_sd(wsi)->events |= EPOLLIN;
+
+		sd_event_source_set_io_events(wsi_to_priv_sd(wsi)->source,
+					      wsi_to_priv_sd(wsi)->events);
+		sd_event_source_set_enabled(wsi_to_priv_sd(wsi)->source,
+					    SD_EVENT_ONESHOT);
+	} else {
+		if (flags & LWS_EV_WRITE)
+			wsi_to_priv_sd(wsi)->events =
+				wsi_to_priv_sd(wsi)->events &
+					(uint32_t)(~EPOLLOUT);
+
+		if (flags & LWS_EV_READ)
+			wsi_to_priv_sd(wsi)->events =
+				wsi_to_priv_sd(wsi)->events &
+					(uint32_t)(~EPOLLIN);
+
+		sd_event_source_set_io_events(wsi_to_priv_sd(wsi)->source,
+					      wsi_to_priv_sd(wsi)->events);
+
+		if (!(wsi_to_priv_sd(wsi)->events & (EPOLLIN | EPOLLOUT)))
+			sd_event_source_set_enabled(wsi_to_priv_sd(wsi)->source,
+						    SD_EVENT_ONESHOT);
+		else
+			sd_event_source_set_enabled(wsi_to_priv_sd(wsi)->source,
+						    SD_EVENT_OFF);
+	}
+}
+
+static int
+init_vhost_listen_wsi_sd(struct lws *wsi)
+{
+	struct lws_context_per_thread *pt;
+
+	if (!wsi)
+		return 0;
+
+	pt = &wsi->a.context->pt[(int)wsi->tsi];
+
+	sd_event_add_io(pt_to_priv_sd(pt)->io_loop,
+			&wsi_to_priv_sd(wsi)->source,
+			wsi->desc.sockfd,
+			wsi_to_priv_sd(wsi)->events,
+			sock_accept_handler,
+			wsi);
+
+	io_sd(wsi, LWS_EV_START | LWS_EV_READ);
+
+	return 0;
+}
+
+static int
+init_pt_sd(struct lws_context *context, void *_loop, int tsi)
+{
+	struct lws_context_per_thread *pt = &context->pt[tsi];
+	struct lws_pt_eventlibs_sdevent *ptpriv = pt_to_priv_sd(pt);
+	struct sd_event *loop = (struct sd_event *)_loop;
+	struct lws_vhost *vh;
+	int first = 1;  // we are the first that create and initialize the loop
+
+	ptpriv->pt = pt;
+
+	// make sure we have an event loop
+	if (!ptpriv->io_loop) {
+		if (!loop) {
+			if (sd_event_default(&loop) < 0) {
+				lwsl_err("%s: sd_event_default failed\n", __func__);
+
+				return -1;
+			}
+			pt->event_loop_foreign = 0;
+		} else {
+			sd_event_ref(loop);
+			pt->event_loop_foreign = 1;
+		}
+
+		ptpriv->io_loop = loop;
+
+	} else
+		 /*
+		  * If the loop was initialized before, we do not need to
+		  * do full initialization
+		  */
+		first = 0;
+
+	// initialize accept/read for vhosts
+	// Note: default vhost usually not included here
+	for (vh = context->vhost_list; vh; vh = vh->vhost_next)
+		/* call lws_event_loop_ops->init_vhost_listen_wsi */
+		if (init_vhost_listen_wsi_sd(vh->lserv_wsi) == -1)
+			return -1;
+
+	if (first) {
+
+		if (0 > sd_event_add_time(loop,
+				&ptpriv->sultimer,
+				CLOCK_MONOTONIC,
+				UINT64_MAX,
+				0,
+				sultimer_handler,
+				(void*) pt
+		))
+			return -1;
+
+		if (0 > sd_event_add_time(loop,
+				&ptpriv->idletimer,
+				CLOCK_MONOTONIC,
+				0,
+				0,
+				idle_handler,
+				(void *)pt))
+			return -1;
+
+		sd_event_source_set_enabled(ptpriv->idletimer, SD_EVENT_ON);
+
+		if (0 > sd_event_source_set_priority(ptpriv->idletimer,
+						     SD_EVENT_PRIORITY_IDLE))
+			return -1;
+
+	}
+
+	return 0;
+}
+
+static void
+wsi_destroy_sd(struct lws *wsi)
+{
+	if (!wsi)
+		return;
+
+	io_sd(wsi, LWS_EV_STOP | (LWS_EV_READ | LWS_EV_WRITE));
+
+	if (wsi_to_priv_sd(wsi)->source) {
+		sd_event_source_set_enabled(wsi_to_priv_sd(wsi)->source,
+					    SD_EVENT_OFF);
+		sd_event_source_unref(wsi_to_priv_sd(wsi)->source);
+		wsi_to_priv_sd(wsi)->source = NULL;
+	}
+}
+
+static int
+wsi_logical_close_sd(struct lws *wsi)
+{
+	wsi_destroy_sd(wsi);
+
+	return 0;
+}
+
+static int
+sock_accept_sd(struct lws *wsi)
+{
+	struct lws_context_per_thread *pt = &wsi->a.context->pt[(int)wsi->tsi];
+
+	if (wsi->role_ops->file_handle)
+		sd_event_add_io(pt_to_priv_sd(pt)->io_loop,
+				&wsi_to_priv_sd(wsi)->source,
+				wsi->desc.filefd,
+				wsi_to_priv_sd(wsi)->events,
+				sock_accept_handler,
+				wsi);
+	else
+		sd_event_add_io(pt_to_priv_sd(pt)->io_loop,
+				&wsi_to_priv_sd(wsi)->source,
+				wsi->desc.sockfd,
+				wsi_to_priv_sd(wsi)->events,
+				sock_accept_handler,
+				wsi);
+
+	return 0;
+}
+
+static void
+run_pt_sd(struct lws_context *context, int tsi)
+{
+	struct lws_context_per_thread *pt = &context->pt[tsi];
+	struct lws_pt_eventlibs_sdevent *ptpriv = pt_to_priv_sd(pt);
+
+	if (ptpriv->io_loop)
+		sd_event_run(ptpriv->io_loop, (uint64_t) -1);
+}
+
+static void
+destroy_pt_sd(struct lws_context *context, int tsi)
+{
+	struct lws_context_per_thread *pt = &context->pt[tsi];
+	struct lws_pt_eventlibs_sdevent *ptpriv = pt_to_priv_sd(pt);
+	struct lws_vhost *vh;
+
+	for (vh = context->vhost_list; vh; vh = vh->vhost_next)
+		if (vh->lserv_wsi)
+			wsi_logical_close_sd(vh->lserv_wsi);
+
+	if (ptpriv->sultimer) {
+		sd_event_source_set_enabled(ptpriv->sultimer,
+					    SD_EVENT_OFF);
+		sd_event_source_unref(ptpriv->sultimer);
+		ptpriv->sultimer = NULL;
+	}
+
+	if (ptpriv->idletimer) {
+		sd_event_source_set_enabled(ptpriv->idletimer,
+					    SD_EVENT_OFF);
+		sd_event_source_unref(ptpriv->idletimer);
+		ptpriv->idletimer = NULL;
+	}
+
+	if (ptpriv->io_loop) {
+		sd_event_unref(ptpriv->io_loop);
+		ptpriv->io_loop = NULL;
+	}
+
+}
+
+const struct lws_event_loop_ops event_loop_ops_sdevent = {
+		.name				= "sdevent",
+		.init_context			= NULL,
+		.destroy_context1		= NULL,
+		.destroy_context2		= NULL,
+		.init_vhost_listen_wsi		= init_vhost_listen_wsi_sd,
+		.init_pt			= init_pt_sd,
+		.wsi_logical_close		= wsi_logical_close_sd,
+		.check_client_connect_ok	= NULL,
+		.close_handle_manually		= NULL,
+		.sock_accept			= sock_accept_sd,
+		.io				= io_sd,
+		.run_pt				= run_pt_sd,
+		.destroy_pt			= destroy_pt_sd,
+		.destroy_wsi			= wsi_destroy_sd,
+
+		.flags				= 0,
+
+		.evlib_size_ctx			= 0,
+		.evlib_size_pt			= sizeof(struct lws_pt_eventlibs_sdevent),
+		.evlib_size_vh			= 0,
+		.evlib_size_wsi			= sizeof(struct lws_wsi_watcher_sdevent),
+};
+
+#if defined(LWS_WITH_EVLIB_PLUGINS)
+LWS_VISIBLE
+#endif
+const lws_plugin_evlib_t evlib_sd = {
+		.hdr = {
+				"systemd event loop",
+				"lws_evlib_plugin",
+				LWS_PLUGIN_API_MAGIC
+		},
+
+		.ops	= &event_loop_ops_sdevent
+};
diff --git a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/CMakeLists.txt b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/CMakeLists.txt
index 5bf00224f..123e81309 100644
--- a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/CMakeLists.txt
+++ b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/CMakeLists.txt
@@ -19,7 +19,7 @@ CHECK_C_SOURCE_COMPILES("#include <libwebsockets.h>\nint main(void) {\n#if defin
 CHECK_C_SOURCE_COMPILES("#include <libwebsockets.h>\nint main(void) {\n#if defined(LWS_WITH_LIBEVENT)\n return 0;\n#else\n fail;\n#endif\n return 0;\n}\n" LWS_WITH_LIBEVENT)
 CHECK_C_SOURCE_COMPILES("#include <libwebsockets.h>\nint main(void) {\n#if defined(LWS_WITH_LIBEV)\n return 0;\n#else\n fail;\n#endif\n return 0;\n}\n" LWS_WITH_LIBEV)
 CHECK_C_SOURCE_COMPILES("#include <libwebsockets.h>\nint main(void) {\n#if defined(LWS_WITH_GLIB)\n return 0;\n#else\n fail;\n#endif\n return 0;\n}\n" LWS_WITH_GLIB)
-
+CHECK_C_SOURCE_COMPILES("#include <libwebsockets.h>\nint main(void) {\n#if defined(LWS_WITH_SDEVENT)\n return 0;\n#else\n fail;\n#endif\n return 0;\n}\n" LWS_WITH_SDEVENT)
 
 if (LWS_WITH_LIBUV)
 	find_path(LIBUV_INCLUDE_DIRS NAMES uv.h)
@@ -72,6 +72,16 @@ if (LWS_WITH_GLIB)
 	set(extralibs ${extralibs} ${GLIB_LIBRARIES})
 	list(APPEND SRCS glib.c)
 endif()
+if (LWS_WITH_SDEVENT)
+	find_path(LIBSYSTEMD_INCLUDE_DIRS NAMES systemd/sd-event.h)
+	find_library(LIBSYSTEMD_LIBRARIES NAMES systemd)
+	message("libsystemd include dir: ${LIBSYSTEMD_INCLUDE_DIRS}")
+	message("libsystemd libraries: ${LIBSYSTEMD_LIBRARIES}")
+	include_directories("${LIBSYSTEMD_INCLUDE_DIRS}")
+	set(extralibs ${extralibs} ${LIBSYSTEMD_LIBRARIES})
+	list(APPEND SRCS libsdevent.c)
+endif()
+
 
 message("Extra libs: ${extralibs}")
 
diff --git a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/README.md b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/README.md
index 4c21fa1a9..0a4aa5f89 100644
--- a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/README.md
+++ b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/README.md
@@ -6,6 +6,7 @@ Commandline option|Meaning
 --uv|Use the libuv event library (lws must have been configured with `-DLWS_WITH_LIBUV=1`)
 --event|Use the libevent library (lws must have been configured with `-DLWS_WITH_LIBEVENT=1`)
 --ev|Use the libev event library (lws must have been configured with `-DLWS_WITH_LIBEV=1`)
+--sd|Use the systemd event library (lws must have been configured with `-DLWS_WITH_SDEVENT=1`)
 
 Notice libevent and libev cannot coexist in the one library.  But all the other combinations are OK.
 
diff --git a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/libsdevent.c b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/libsdevent.c
new file mode 100644
index 000000000..bc712c433
--- /dev/null
+++ b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/libsdevent.c
@@ -0,0 +1,86 @@
+/*
+ * lws-minimal-http-server-eventlib-foreign
+ *
+ * Written in 2020 by Christian Fuchs <christian.fuchs@scs.ch>
+ *
+ * This file is made available under the Creative Commons CC0 1.0
+ * Universal Public Domain Dedication.
+ *
+ * The sdevent specific code
+ */
+
+#include <libwebsockets.h>
+
+#include <string.h>
+#include <signal.h>
+
+#include <systemd/sd-event.h>
+
+#include "private.h"
+
+static struct sd_event *sd_loop;
+static sd_event_source *sd_timer;
+static sd_event_source *sd_signal;
+
+static int
+timer_cb_sd(sd_event_source *source, uint64_t now, void *user)
+{
+	foreign_timer_service(sd_loop);
+
+	if (sd_timer) {
+		sd_event_source_set_time(sd_timer, now + 1000000);
+		sd_event_source_set_enabled(sd_timer, SD_EVENT_ON);
+	}
+
+	return 0;
+}
+
+static int
+signal_cb_sd(sd_event_source *source, const struct signalfd_siginfo *si,
+             void *user)
+{
+	signal_cb((int)si->ssi_signo);
+	return 0;
+}
+
+static void
+foreign_event_loop_init_and_run_libsdevent(void)
+{
+	uint64_t now;
+
+	/* we create and start our "foreign loop" */
+
+	sd_event_default(&sd_loop);
+	sd_event_add_signal(sd_loop, &sd_signal, SIGINT, signal_cb_sd, NULL);
+
+	sd_event_now(sd_loop, CLOCK_MONOTONIC, &now);
+	sd_event_add_time(sd_loop, &sd_timer, CLOCK_MONOTONIC, now,
+			  (uint64_t) 1000, timer_cb_sd, NULL);
+
+	sd_event_loop(sd_loop);
+}
+
+static void
+foreign_event_loop_stop_libsdevent(void)
+{
+	sd_event_exit(sd_loop, 0);
+}
+
+static void
+foreign_event_loop_cleanup_libsdevent(void)
+{
+	sd_event_source_set_enabled(sd_timer, SD_EVENT_OFF);
+	sd_timer = sd_event_source_unref(sd_timer);
+
+	sd_event_source_set_enabled(sd_signal, SD_EVENT_OFF);
+	sd_signal = sd_event_source_unref(sd_signal);
+
+	sd_loop = sd_event_unref(sd_loop);
+}
+
+const struct ops ops_sdevent = {
+	foreign_event_loop_init_and_run_libsdevent,
+	foreign_event_loop_stop_libsdevent,
+	foreign_event_loop_cleanup_libsdevent
+};
+
diff --git a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/minimal-http-server-eventlib-foreign.c b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/minimal-http-server-eventlib-foreign.c
index de289fb4a..ff9a8973b 100644
--- a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/minimal-http-server-eventlib-foreign.c
+++ b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/minimal-http-server-eventlib-foreign.c
@@ -196,10 +196,17 @@ int main(int argc, const char **argv)
 					ops = &ops_glib;
 					lwsl_notice("%s: using glib loop\n", __func__);
 				} else
+#endif
+#if defined(LWS_WITH_SDEVENT)
+					if (lws_cmdline_option(argc, argv, "--sd")) {
+						info.options |= LWS_SERVER_OPTION_SDEVENT;
+						ops = &ops_sdevent;
+						lwsl_notice("%s: using sd-event loop\n", __func__);
+					} else
 #endif
 				{
 				lwsl_err("This app only makes sense when used\n");
-				lwsl_err(" with a foreign loop, --uv, --event, --glib, or --ev\n");
+				lwsl_err(" with a foreign loop, --uv, --event, --glib, --ev or --sd\n");
 
 				return 1;
 				}
diff --git a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/private.h b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/private.h
index 71dfd2191..8f41c4721 100644
--- a/minimal-examples/http-server/minimal-http-server-eventlib-foreign/private.h
+++ b/minimal-examples/http-server/minimal-http-server-eventlib-foreign/private.h
@@ -12,4 +12,4 @@ extern int lifetime, reported;
 void foreign_timer_service(void *foreign_loop);
 void signal_cb(int signum);
 
-extern const struct ops ops_libuv, ops_libevent, ops_glib, ops_libev;
+extern const struct ops ops_libuv, ops_libevent, ops_glib, ops_libev, ops_sdevent;