diff --git a/core/src/stl.rs b/core/src/stl.rs
index c67fdf9..b405842 100644
--- a/core/src/stl.rs
+++ b/core/src/stl.rs
@@ -23,7 +23,6 @@ pub mod control;
 pub mod decl;
 pub mod math;
 pub mod strings;
-pub mod file;
 
 pub const CFG_FILE_VNAME: &str = "FLESH_CFG_FILE";
 
@@ -37,5 +36,4 @@ pub fn static_stdlib(syms: &mut SymTable) {
     control::add_control_lib(syms);
     boolean::add_bool_lib(syms);
     math::add_math_lib(syms);
-    file::add_file_lib(syms);
 }
diff --git a/core/tests/test_lib_file.rs b/core/tests/test_lib_file.rs
deleted file mode 100644
index 729d5ad..0000000
--- a/core/tests/test_lib_file.rs
+++ /dev/null
@@ -1,76 +0,0 @@
-mod file_lib_tests {
-    use flesh::ast::{eval, lex, SymTable};
-    use flesh::stdlib::static_stdlib;
-
-    #[test]
-    fn test_fexists() {
-        let document = "(exists? \"/tmp\")";
-        let result = "true";
-
-        let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
-        assert_eq!(
-            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
-                .unwrap()
-                .to_string(),
-            result.to_string(),
-        );
-    }
-
-    #[test]
-    fn test_fexists_doesnt() {
-        let document = "(exists? \"cargo.timtam\")";
-        let result = "false";
-
-        let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
-        assert_eq!(
-            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
-                .unwrap()
-                .to_string(),
-            result.to_string(),
-        );
-    }
-
-    #[test]
-    fn test_write_file() {
-        let document = "
-          (let ((s \"test\")
-                (t \"/tmp/flesh-lib-test-file-1\"))
-            (write-file t s)
-            (echo (read-file t))
-            (eq? (read-file t) s))";
-        let result = "true";
-
-        let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
-        assert_eq!(
-            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
-                .unwrap()
-                .to_string(),
-            result.to_string(),
-        );
-    }
-
-    #[test]
-    fn test_append_file() {
-        let document = "
-          (let ((s \"test\")
-                (t \"/tmp/flesh-lib-test-file-2\"))
-            (write-file t s)
-            (append-file t s)
-            (eq? (read-file t)
-                (concat s s)))";
-        let result = "true";
-
-        let mut syms = SymTable::new();
-        static_stdlib(&mut syms);
-        assert_eq!(
-            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
-                .unwrap()
-                .to_string(),
-            result.to_string(),
-        );
-    }
-
-}
diff --git a/core/src/stl/file.rs b/shell/src/file.rs
similarity index 73%
rename from core/src/stl/file.rs
rename to shell/src/file.rs
index badb7f5..80208db 100644
--- a/core/src/stl/file.rs
+++ b/shell/src/file.rs
@@ -15,9 +15,11 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-use crate::segment::{Ctr, Seg, Type};
-use crate::sym::{SymTable, Symbol, ValueType, Args};
-use crate::error::{Traceback, start_trace};
+use flesh::ast::{
+    start_trace, Ctr, Seg, Type, SymTable,
+    Symbol, ValueType, Args, Traceback,
+};
+
 use std::io::Write;
 use std::fs::{File, read_to_string, OpenOptions};
 use std::rc::Rc;
@@ -170,3 +172,81 @@ pub fn add_file_lib(syms: &mut SymTable) {
     );
 
 }
+
+#[cfg(test)]
+mod tests {
+    use flesh::ast::{eval, lex, SymTable};
+    use flesh::stdlib::static_stdlib;
+    use crate::stl::static_stdlib_overwrites;
+
+    #[test]
+    fn test_fexists() {
+        let document = "(exists? \"/tmp\")";
+        let result = "true";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms);
+        static_stdlib_overwrites(&mut syms);
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+
+    #[test]
+    fn test_fexists_doesnt() {
+        let document = "(exists? \"cargo.timtam\")";
+        let result = "false";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms);
+        static_stdlib_overwrites(&mut syms);
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+
+    #[test]
+    fn test_write_file() {
+        let document = "
+          (let ((s \"test\")
+                (t \"/tmp/flesh-lib-test-file-1\"))
+            (write-file t s)
+            (echo (read-file t))
+            (eq? (read-file t) s))";
+        let result = "true";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms);
+        static_stdlib_overwrites(&mut syms);
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+
+    #[test]
+    fn test_append_file() {
+        let document = "
+          (let ((s \"test\")
+                (t \"/tmp/flesh-lib-test-file-2\"))
+            (write-file t s)
+            (append-file t s)
+            (eq? (read-file t)
+                (concat s s)))";
+        let result = "true";
+        let mut syms = SymTable::new();
+        static_stdlib(&mut syms);
+        static_stdlib_overwrites(&mut syms);
+        assert_eq!(
+            *eval(&lex(&document.to_string()).unwrap(), &mut syms)
+                .unwrap()
+                .to_string(),
+            result.to_string(),
+        );
+    }
+}
diff --git a/shell/src/stl.rs b/shell/src/stl.rs
index 3f1669a..8638887 100644
--- a/shell/src/stl.rs
+++ b/shell/src/stl.rs
@@ -31,8 +31,10 @@ use crate::posix;
 
 #[path = "window.rs"]
 mod window;
-#[path = "store.rs"] 
+#[path = "store.rs"]
 mod store;
+#[path = "file.rs"]
+mod file;
 
 pub const CONSOLE_XDIM_VNAME: &str = "_FLESH_WIDTH";
 pub const CONSOLE_YDIM_VNAME: &str = "_FLESH_HEIGHT";
@@ -63,6 +65,7 @@ fn prompt_delimiter_default_callback(_: &Seg, _: &mut SymTable) -> Result<Ctr, T
 pub fn static_stdlib_overwrites(syms: &mut SymTable) {
     static_stdlib(syms);
     window::add_window_lib_funcs(syms);
+    file::add_file_lib(syms);
 
     syms.insert(
         "call".to_string(),