diff --git a/runall.py b/runall.py
index 691086b..b29cdab 100644
--- a/runall.py
+++ b/runall.py
@@ -6,7 +6,15 @@ chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ!"#$%&\'(
 
 def check_pair(script, instr, outstr):
     result = subprocess.run(
-        ["/usr/bin/env", "bash", "-c", script],
+        [
+            "/usr/bin/env", "bash", "-c",
+            ";\n".join((
+                # Cleanup child processes on exit
+                "trap 'kill -9 $(jobs -p)' SIGINT SIGTERM EXIT",
+                script,
+            ))
+        ],
+        timeout=5,
         input=instr.encode(),
         capture_output=True,
     )