diff --git a/src/memory/types.rs b/src/memory/types.rs
index de0f585..77ffd67 100644
--- a/src/memory/types.rs
+++ b/src/memory/types.rs
@@ -1,12 +1,12 @@
+use serde::{Deserialize, Serialize};
 use std::fmt;
-
 pub type ID = String;
 pub type StackPage = Vec<Entry>;
 pub type FilePage = (String, Vec<f32>);
 
 /// Entry is an enum that can be either a String or a Json Value.
 /// It is used for I/O operations in the memory module.
-#[derive(Debug, serde::Deserialize, PartialEq)]
+#[derive(Debug, Serialize, serde::Deserialize, PartialEq)]
 pub enum Entry {
     String(String),
     Json(serde_json::Value),
@@ -39,7 +39,7 @@ impl Clone for Entry {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Serialize, Deserialize)]
 pub enum MemoryReturnType {
     //<'a>
     //EntryRef(Option<&'a Entry>),
@@ -55,6 +55,10 @@ impl MemoryReturnType {
             MemoryReturnType::EntryVec(entry_vec) => entry_vec.is_none(),
         }
     }
+
+    pub fn to_json(&self) -> serde_json::Result<String> {
+        serde_json::to_string(&self)
+    }
 }
 
 impl fmt::Display for MemoryReturnType {
diff --git a/src/program/executor.rs b/src/program/executor.rs
index f088170..70fd21d 100644
--- a/src/program/executor.rs
+++ b/src/program/executor.rs
@@ -206,6 +206,13 @@ impl Executor {
                 };
             }
         }
+
+        if rv.to_json.is_some() && rv.to_json.unwrap() {
+            let res = return_value.to_json();
+            if res.is_ok() {
+                return_string = res.unwrap();
+            }
+        }
         return_string
     }