diff --git a/src/meta_plugin/mod.rs b/src/meta_plugin/mod.rs
index 685f7c0..d17d38e 100644
--- a/src/meta_plugin/mod.rs
+++ b/src/meta_plugin/mod.rs
@@ -5,6 +5,7 @@ use std::sync::Mutex;
 use once_cell::sync::Lazy;
 
 pub mod exec;
+use crate::meta_plugin::exec::MetaPluginExec;
 pub mod digest;
 pub mod magic;
 pub mod text;
@@ -107,7 +108,7 @@ impl MetaPlugin for BaseMetaPlugin {
     }
 }
 
-#[derive(Debug, Eq, PartialEq, Clone, strum::EnumIter, strum::Display, strum::EnumString, Serialize, Deserialize)]
+#[derive(Debug, Eq, PartialEq, Clone, Hash, strum::EnumIter, strum::Display, strum::EnumString, Serialize, Deserialize)]
 #[strum(serialize_all = "snake_case", ascii_case_insensitive)]
 pub enum MetaPluginType {
     MagicFile,
@@ -233,8 +234,6 @@ pub trait MetaPlugin where Self: 'static {
     // Access to outputs mapping with default implementation
     fn outputs(&self) -> &std::collections::HashMap<String, serde_yaml::Value> {
         use once_cell::sync::Lazy;
-        use std::collections::HashMap;
-        use std::sync::Mutex;
         static EMPTY: Lazy<std::collections::HashMap<String, serde_yaml::Value>> = 
             Lazy::new(|| std::collections::HashMap::new());
         &EMPTY