diff --git a/os/run/chroot_loader.run b/os/run/chroot_loader.run
index a27747278..95d35b615 100644
--- a/os/run/chroot_loader.run
+++ b/os/run/chroot_loader.run
@@ -10,7 +10,7 @@ if {![have_spec linux]} { puts "Run script requires Linux"; exit 0 }
 # Build
 #
 
-build { core init drivers/timer/linux test/timer
+build { core init drivers/timer test/timer
         server/loader test/chroot_loader }
 
 if {[catch { exec which setcap }]} {
@@ -18,6 +18,23 @@ if {[catch { exec which setcap }]} {
 	return 0
 }
 
+#
+# Clean up remains of a potentially failed previous run
+#
+
+proc chroot_path     { id } { return "/tmp/chroot-test-$id" }
+proc chroot_cwd_path { id } { return "[chroot_path $id][pwd]/[run_dir]" }
+
+proc cleanup_chroot { } {
+
+	foreach id { 1 2 } {
+		umount_and_rmdir [chroot_cwd_path $id]
+		umount_and_rmdir [chroot_path $id]/lib
+		umount_and_rmdir [chroot_path $id]/lib64
+	}
+}
+
+cleanup_chroot
 
 create_boot_directory
 
@@ -58,18 +75,6 @@ set config {
 	</config>
 }
 
-proc chroot_path     { id } { return "/tmp/chroot-test-$id" }
-proc chroot_cwd_path { id } { return "[chroot_path $id][pwd]/[run_dir]" }
-
-proc cleanup_chroot { } {
-
-	foreach id { 1 2 } {
-		umount_and_rmdir [chroot_cwd_path $id]
-		umount_and_rmdir [chroot_path $id]/lib
-		umount_and_rmdir [chroot_path $id]/lib64
-	}
-}
-
 # replace 'chroot_path' markers in config with actual paths
 foreach id { 1 2 } {
 	regsub "chroot_path_$id" $config [chroot_path $id] config }
@@ -100,7 +105,6 @@ exec sudo setcap cap_sys_admin,cap_sys_chroot=ep [run_dir]/core
 #
 
 # start with fresh directory
-cleanup_chroot
 foreach id { 1 2 } {
 	exec mkdir -p [chroot_path $id]
 	exec mkdir -p [chroot_path $id]/lib
@@ -125,7 +129,7 @@ if {[regexp -all -- {--- timer test ---} $output] != 6} {
 	exit 2
 }
 
-if {![regexp -- {init-1 -> test-timer] wait 2/10} $output]} {
+if {![regexp -- {init-1 -> test-timer] Done 500 ms period 4 times} $output]} {
 	puts stderr "Long-running timer test has made too little progress"
 	exit 3
 }
@@ -135,4 +139,7 @@ if {![regexp -- {init-1 -> test-timer] wait 2/10} $output]} {
 #
 cleanup_chroot
 
+puts "Test succeeded"
+
 # vi: set ft=tcl :
+
diff --git a/os/src/test/chroot_loader/main.cc b/os/src/test/chroot_loader/main.cc
index 5015cbee2..98379548e 100644
--- a/os/src/test/chroot_loader/main.cc
+++ b/os/src/test/chroot_loader/main.cc
@@ -61,6 +61,7 @@ static char const *subsystem_config()
 	       "    <service name=\"CPU\"/>\n"
 	       "    <service name=\"RM\"/>\n"
 	       "    <service name=\"PD\"/>\n"
+	       "    <service name=\"SIGNAL\"/>\n"
 	       "    <service name=\"Timer\"/>\n"
 	       "  </parent-provides>\n"
 	       "  <default-route>\n"