diff --git a/config/config.go b/config/config.go
index c561110f..1d87c849 100644
--- a/config/config.go
+++ b/config/config.go
@@ -432,7 +432,7 @@ func (c *Config) UnmarshalYAML(unmarshal func(interface{}) error) error {
 		return fmt.Errorf("root route must not have any matchers")
 	}
 	if len(c.Route.MuteTimeIntervals) > 0 {
-		return fmt.Errorf("root route cannot have any mute times")
+		return fmt.Errorf("root route must not have any mute time intervals")
 	}
 
 	// Validate that all receivers used in the routing tree are defined.
diff --git a/config/config_test.go b/config/config_test.go
index 0fe587cd..ce8c6fef 100644
--- a/config/config_test.go
+++ b/config/config_test.go
@@ -347,7 +347,7 @@ route:
 `
 	_, err := Load(in)
 
-	expected := "root route cannot have any mute times"
+	expected := "root route must not have any mute time intervals"
 
 	if err == nil {
 		t.Fatalf("no error returned, expected:\n%q", expected)