diff --git a/src/lib.rs b/src/lib.rs
index 23bac7b..680eb6b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -36,6 +36,6 @@ pub mod ast {
 
 pub mod stdlib {
     pub use crate::stl::{get_stdlib};
-    pub use crate::str::{get_echo};
+    pub use crate::str::{get_echo, get_concat};
     pub use crate::append::{get_append};
 }
diff --git a/src/stl.rs b/src/stl.rs
index 6a4690b..4f19ecf 100644
--- a/src/stl.rs
+++ b/src/stl.rs
@@ -15,7 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-use crate::str::get_echo;
+use crate::str::{get_echo, get_concat};
 use crate::append::get_append;
 use crate::func::{FTable, func_declare};
 use std::rc::Rc;
@@ -29,6 +29,9 @@ pub fn get_stdlib() -> Result<Rc<RefCell<FTable>>, String> {
     if let Some(s) = func_declare(ft.clone(), Rc::new(RefCell::new(get_append()))) {
         return Err(s)
     }
+    if let Some(s) = func_declare(ft.clone(), Rc::new(RefCell::new(get_concat()))) {
+        return Err(s)
+    }
 
     return Ok(ft)
 }
diff --git a/src/str.rs b/src/str.rs
index 44cc125..cf0bb09 100644
--- a/src/str.rs
+++ b/src/str.rs
@@ -43,7 +43,7 @@ pub fn get_echo() -> Function {
                         Ctr::Seg(c)     => string.push_str(ast_as_string(c.clone(), true).as_str()),
                         Ctr::None       => ()
                     }
-                    println!(string)
+                    println!("{}", string);
                     return true;
                 }) {
                     eprintln!("circuit loop in echo should not have returned false")