diff --git a/core/nginx/certwatcher.py b/core/nginx/certwatcher.py
index 0e83666e..48d128ed 100755
--- a/core/nginx/certwatcher.py
+++ b/core/nginx/certwatcher.py
@@ -27,9 +27,9 @@ class ChangeHandler(FileSystemEventHandler):
         if exists("/var/run/nginx.pid"):
             print("Reloading a running nginx")
             system("nginx -s reload")
-        if os.path.exists("/run/dovecot/master.pid"):
+        if exists("/run/dovecot/master.pid"):
             print("Reloading a running dovecot")
-            os.system("doveadm reload")
+            system("doveadm reload")
 
     @staticmethod
     def reexec_config():
diff --git a/towncrier/newsfragments/3420.bugfix b/towncrier/newsfragments/3420.bugfix
new file mode 100644
index 00000000..dbc78435
--- /dev/null
+++ b/towncrier/newsfragments/3420.bugfix
@@ -0,0 +1 @@
+The reload functionality of nginx/dovecot upon change of the certificates failed with an error.
\ No newline at end of file