diff --git a/boefjes/boefjes/plugins/kat_dnssec/main.py b/boefjes/boefjes/plugins/kat_dnssec/main.py
index 950225b1829..9fc385134f2 100644
--- a/boefjes/boefjes/plugins/kat_dnssec/main.py
+++ b/boefjes/boefjes/plugins/kat_dnssec/main.py
@@ -17,4 +17,8 @@ def run(boefje_meta: dict):
     cmd = ["/usr/bin/drill", "-DT", domain]
     output = subprocess.run(cmd, capture_output=True)
 
-    return [({"openkat/dnssec-output"}, output.stdout)]
+    output.check_returncode()
+
+    results = [({"openkat/dnssec-output"}, output.stdout)]
+
+    return results
diff --git a/boefjes/boefjes/plugins/kat_nmap_tcp/main.py b/boefjes/boefjes/plugins/kat_nmap_tcp/main.py
index 41fdaa5cd97..3b14b10292c 100644
--- a/boefjes/boefjes/plugins/kat_nmap_tcp/main.py
+++ b/boefjes/boefjes/plugins/kat_nmap_tcp/main.py
@@ -18,4 +18,10 @@ def run(boefje_meta: dict):
         cmd.append("-6")
 
     cmd.extend(["-oX", "-", str(ip)])
-    return [({"openkat/nmap-output"}, subprocess.run(cmd, capture_output=True).stdout.decode())]
+    output = subprocess.run(cmd, capture_output=True)
+
+    output.check_returncode()
+
+    results = [({"openkat/nmap-output"}, output.stdout.decode())]
+
+    return results