diff --git a/tests/jffs2/test.nix b/tests/jffs2/test.nix
index b50a1e9..7a04b03 100644
--- a/tests/jffs2/test.nix
+++ b/tests/jffs2/test.nix
@@ -15,29 +15,6 @@ in pkgs.runCommand "check" {
     socat
   ] ;
 } ''
-serverstatedir=$(mktemp -d -t routeros-XXXXXX)
-
-killpid(){
-  if test -e $1 && test -d /proc/`cat $1` ; then
-    pid=$(cat $1)
-    kill $pid
-  fi
-}
-
-cleanup(){
-  killpid $serverstatedir/pid
-  test -n "$MPLCONFIGDIR" && test -d "$MPLCONFIGDIR" && rm -rf "$MPLCONFIGDIR"
-  killpid foo.pid
-}
-trap cleanup EXIT
-
-fatal(){
-  err=$?
-  echo "FAIL: command $(eval echo $BASH_COMMAND) exited with code $err"
-  exit $err
-}
-trap fatal ERR
-
 mkdir vm
 mips-vm --background ./vm ${img}/vmlinux ${img}/rootfs
 expect ${./script.expect} >$out
diff --git a/tests/min-copy-closure/test.nix b/tests/min-copy-closure/test.nix
index 48bb726..fc58b68 100644
--- a/tests/min-copy-closure/test.nix
+++ b/tests/min-copy-closure/test.nix
@@ -19,24 +19,7 @@ in pkgs.runCommand "check" {
     rogue
   ] ;
 } ''
-killpid(){
-  if test -e $1 && test -d /proc/`cat $1` ; then
-    pid=$(cat $1)
-    kill $pid
-  fi
-}
-
-cleanup(){
-  killpid ./vm/pid
-}
-
-trap cleanup EXIT
-fatal(){
-    err=$?
-    echo "FAIL: command $(eval echo $BASH_COMMAND) exited with code $err"
-    exit $err
-}
-trap fatal ERR
+. ${../test-helpers.sh}
 
 mkdir vm
 LAN=user,hostfwd=tcp::2022-:22 mips-vm --background ./vm ${img}/vmlinux ${img}/rootfs
diff --git a/tests/pppoe/test.nix b/tests/pppoe/test.nix
index ef51013..c5d261f 100644
--- a/tests/pppoe/test.nix
+++ b/tests/pppoe/test.nix
@@ -23,26 +23,7 @@ serverstatedir=$(mktemp -d -t routeros-XXXXXX)
 # a sandbox with no $HOME, hence this environment variable
 export MPLCONFIGDIR=$(mktemp -d -t routeros-XXXXXX)
 
-killpid(){
-  if test -e $1 && test -d /proc/`cat $1` ; then
-    pid=$(cat $1)
-    kill $pid
-  fi
-}
-
-cleanup(){
-  killpid $serverstatedir/pid
-  test -n "$MPLCONFIGDIR" && test -d "$MPLCONFIGDIR" && rm -rf "$MPLCONFIGDIR"
-  killpid foo.pid
-}
-trap cleanup EXIT
-
-fatal(){
-  err=$?
-  echo "FAIL: command $(eval echo $BASH_COMMAND) exited with code $err"
-  exit $err
-}
-trap fatal ERR
+. ${../test-helpers.sh}
 
 routeros $serverstatedir
 mkdir vm
diff --git a/tests/test-helpers.sh b/tests/test-helpers.sh
new file mode 100644
index 0000000..b9f81e2
--- /dev/null
+++ b/tests/test-helpers.sh
@@ -0,0 +1,21 @@
+killpid(){
+  if test -e $1 && test -d /proc/`cat $1` ; then
+    pid=$(cat $1)
+    kill $pid
+  fi
+}
+
+cleanup(){
+  killpid $serverstatedir/pid
+  test -n "$MPLCONFIGDIR" && test -d "$MPLCONFIGDIR" && rm -rf "$MPLCONFIGDIR"
+  killpid foo.pid
+  killpid ./vm/pid
+}
+trap cleanup EXIT
+
+fatal(){
+  err=$?
+  echo "FAIL: command $(eval echo $BASH_COMMAND) exited with code $err"
+  exit $err
+}
+trap fatal ERR
diff --git a/tests/wlan/test.nix b/tests/wlan/test.nix
index 24e2a3f..4afc38d 100644
--- a/tests/wlan/test.nix
+++ b/tests/wlan/test.nix
@@ -15,23 +15,7 @@ in pkgs.runCommand "check" {
     socat
   ] ;
 } ''
-killpid(){
-  if test -e $1 && test -d /proc/`cat $1` ; then
-    pid=$(cat $1)
-    kill $pid
-  fi
-}
-
-cleanup(){
-  killpid ./vm/pid
-}
-trap cleanup EXIT
-fatal(){
-    err=$?
-    echo "FAIL: command $(eval echo $BASH_COMMAND) exited with code $err"
-    exit $err
-}
-trap fatal ERR
+. ${../test-helpers.sh}
 
 mkdir vm
 mips-vm --background ./vm ${img}/vmlinux ${img}/rootfs