diff --git a/config.go b/config.go
index c4d0109..cde14b6 100644
--- a/config.go
+++ b/config.go
@@ -134,6 +134,11 @@ func readConfig(path string) (*config, error) {
 		}
 	}
 
+	if (config.Password != "" && config.User == "") ||
+		(config.Password == "" && config.User != "") {
+		return nil, errors.New("user and password have to be set together")
+	}
+
 	labelsDir := cfg.Get("labels")
 	if labelsDir != nil {
 		d = labelsDir.Children.Get("order")
@@ -214,6 +219,11 @@ func readConfig(path string) (*config, error) {
 		}
 	}
 
+	if (config.ntfy.Password != "" && config.ntfy.User == "") ||
+		(config.ntfy.Password == "" && config.ntfy.User != "") {
+		return nil, errors.New("ntfy: user and password have to be set together")
+	}
+
 	d = ntfyDir.Children.Get("access-token")
 	if d != nil {
 		if err := d.ParseParams(&config.ntfy.AccessToken); err != nil {
@@ -291,6 +301,11 @@ func readConfig(path string) (*config, error) {
 			}
 		}
 
+		if (config.am.Password != "" && config.am.User == "") ||
+			(config.am.Password == "" && config.am.User != "") {
+			return nil, errors.New("alertmanager: user and password have to be set together")
+		}
+
 		d = amDir.Children.Get("url")
 		if d != nil {
 			if err := d.ParseParams(&config.am.URL); err != nil {