diff --git a/pkg/engine/jmespath/functions.go b/pkg/engine/jmespath/functions.go
index f5141733f2..b0368530da 100644
--- a/pkg/engine/jmespath/functions.go
+++ b/pkg/engine/jmespath/functions.go
@@ -994,13 +994,13 @@ func jpItems(arguments []interface{}) (interface{}, error) {
 	}
 	switch input := arguments[0].(type) {
 	case map[string]interface{}:
-		var keys []string
+		keys := make([]string, 0, len(input))
 		// Sort the keys so that the output is deterministic
 		for key := range input {
 			keys = append(keys, key)
 		}
 		sort.Strings(keys)
-		var arrayOfObj []map[string]interface{}
+		arrayOfObj := make([]map[string]interface{}, 0, len(input))
 		for _, key := range keys {
 			arrayOfObj = append(arrayOfObj, map[string]interface{}{
 				keyName: key,
@@ -1009,7 +1009,7 @@ func jpItems(arguments []interface{}) (interface{}, error) {
 		}
 		return arrayOfObj, nil
 	case []interface{}:
-		var arrayOfObj []map[string]interface{}
+		arrayOfObj := make([]map[string]interface{}, 0, len(input))
 		for index, value := range input {
 			arrayOfObj = append(arrayOfObj, map[string]interface{}{
 				keyName: float64(index),
@@ -1018,7 +1018,7 @@ func jpItems(arguments []interface{}) (interface{}, error) {
 		}
 		return arrayOfObj, nil
 	default:
-		return nil, fmt.Errorf(invalidArgumentTypeError, arguments, 0, "Object")
+		return nil, fmt.Errorf(invalidArgumentTypeError, arguments, 0, "Object or Array")
 	}
 }