diff --git a/Rakefile b/Rakefile
index 590db27..ba5c813 100644
--- a/Rakefile
+++ b/Rakefile
@@ -96,8 +96,23 @@ file check("acl") =>
   gcc_link t.name, t.prerequisites + [LIBCHECK]
 end
 
+file check("serve") =>
+%w{tests/check_serve.c
+  build/self_pipe.o
+  build/nbdtypes.o
+  build/control.o
+  build/readwrite.o
+  build/parse.o
+  build/client.o
+  build/serve.o 
+  build/acl.o
+  build/ioutil.o 
+  build/util.o} do |t|
+  gcc_link t.name, t.prerequisites + [LIBCHECK]
+end
 
-(TEST_MODULES- %w{acl client}).each do |m|
+
+(TEST_MODULES- %w{acl client serve}).each do |m|
   deps = ["tests/check_#{m}.c", "build/ioutil.o", "build/util.o"]
   maybe_obj_name = "build/#{m}.o"
 
diff --git a/src/control.c b/src/control.c
index 67e7c30..8c36212 100644
--- a/src/control.c
+++ b/src/control.c
@@ -273,8 +273,7 @@ int control_acl(struct control_params* client, int linesc, char** lines)
 		acl_destroy( new_acl );
 	}
 	else {
-		client->serve->acl = new_acl;
-		acl_destroy( old_acl );
+		server_replace_acl( client->serve, new_acl );
 		write_socket("0: updated");
 	}
 	
diff --git a/src/serve.c b/src/serve.c
index b6e5000..384780b 100644
--- a/src/serve.c
+++ b/src/serve.c
@@ -314,6 +314,20 @@ void server_close_clients( struct server *params )
 }
 
 
+void server_replace_acl( struct server *serve, struct acl * new_acl )
+{
+	NULLCHECK(serve);
+	NULLCHECK(new_acl);
+
+	struct acl * old_acl = serve->acl;
+
+	serve->acl = new_acl;
+
+	if ( old_acl ) { acl_destroy( old_acl ); }
+	self_pipe_signal( serve->acl_updated_signal );
+}
+
+
 /** Accept either an NBD or control socket connection, dispatch appropriately */
 void serve_accept_loop(struct server* params) 
 {
@@ -402,6 +416,7 @@ void serve_cleanup(struct server* params)
 		close(params->proxy_fd);
 
 	self_pipe_destroy( params->close_signal );
+	self_pipe_destroy( params->acl_updated_signal );
 
 	free(params->allocation_map);
 	
@@ -426,9 +441,9 @@ void do_serve(struct server* params)
 	pthread_mutex_init(&params->l_io, NULL);
 
 	params->close_signal = self_pipe_create();
-	if ( NULL == params->close_signal) { 
-		SERVER_ERROR( "close signal creation failed" ); 
-	}
+	NULLCHECK( params->close_signal );
+	params->acl_updated_signal = self_pipe_create();
+	NULLCHECK( params->acl_updated_signal );
 	
 	serve_open_server_socket(params);
 	serve_open_control_socket(params);
diff --git a/src/serve.h b/src/serve.h
index f96222b..3d0d4c4 100644
--- a/src/serve.h
+++ b/src/serve.h
@@ -3,14 +3,14 @@
 
 #define _GNU_SOURCE
 
-#ifndef _LARGEFILE64_SOURCE
-# define _LARGEFILE64_SOURCE
-#endif
+#define _LARGEFILE64_SOURCE
+
+#include <sys/types.h>
+#include <unistd.h>
 
 #include "parse.h"
 #include "acl.h"
 
-#include <sys/types.h>
 
 static const int block_allocation_resolution = 4096;//128<<10;
 
@@ -69,6 +69,11 @@ struct server {
 	/** to interrupt accept loop and clients, write() to close_signal[1] */
 	struct self_pipe *   close_signal;
 
+	/** acl_updated_signal will be signalled after the acl struct
+	 * has been replaced
+	 */
+	struct self_pipe *   acl_updated_signal;
+
 	struct mirror_status* mirror;
 	int                  server_fd;
 	int                  control_fd;
diff --git a/tests/check_serve.c b/tests/check_serve.c
new file mode 100644
index 0000000..b14c93d
--- /dev/null
+++ b/tests/check_serve.c
@@ -0,0 +1,65 @@
+#include "serve.h"
+#include "self_pipe.h"
+
+#include <check.h>
+#include <stdio.h>
+
+
+START_TEST( test_replaces_acl )
+{
+	struct server s;
+	s.acl_updated_signal = self_pipe_create();
+	struct acl * acl = acl_create( 0, NULL, 0 );
+
+	server_replace_acl( &s, acl );
+
+	fail_unless( s.acl == acl, "ACL wasn't replaced." );
+	self_pipe_destroy( s.acl_updated_signal );
+}
+END_TEST
+
+
+START_TEST( test_signals_acl_updated )
+{
+	struct server s;
+	struct acl * new_acl = acl_create( 0, NULL, 0 );
+
+	s.acl_updated_signal = self_pipe_create();
+	s.acl = acl_create( 0, NULL, 0);
+
+
+	server_replace_acl( &s, new_acl );
+
+	fail_unless( 1 == self_pipe_signal_clear( s.acl_updated_signal ), 
+			"No signal sent." );
+	self_pipe_destroy( s.acl_updated_signal );
+}
+END_TEST
+
+
+Suite* serve_suite()
+{
+	Suite *s = suite_create("serve");
+	TCase *tc_acl_update = tcase_create("acl_update");
+	
+	tcase_add_test(tc_acl_update, test_replaces_acl);
+	tcase_add_test(tc_acl_update, test_signals_acl_updated);
+
+	suite_add_tcase(s, tc_acl_update);
+
+	return s;
+}
+
+
+int main(void)
+{
+	set_debug(1);
+	int number_failed;
+	Suite *s = serve_suite();
+	SRunner *sr = srunner_create(s);
+	srunner_run_all(sr, CK_NORMAL);
+	number_failed = srunner_ntests_failed(sr);
+	srunner_free(sr);
+	return (number_failed == 0) ? 0 : 1;
+}
+