diff --git a/verifier/rules.go b/verifier/rules.go
index cac2ebb..1d1f053 100644
--- a/verifier/rules.go
+++ b/verifier/rules.go
@@ -142,10 +142,13 @@ func applyAttributeRules(env *cel.Env, input interpreter.Activation, rules []Con
 		switch result := out.Value().(type) {
 		case bool:
 			if !result {
-				message := fmt.Sprintf("verification failed for rule '%s'", r.Rule)
+				var message string
 				if r.Debug != "" {
 					message = fmt.Sprintf("%s\nin rule '%s'", r.Debug, r.Rule)
+				} else {
+					message = fmt.Sprintf("verification failed for rule '%s'", r.Rule)
 				}
+
 				if !r.Warn {
 					return fmt.Errorf(message)
 				}