diff --git a/.gitignore b/.gitignore
index 25bb9a4..ab61240 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /target
 .DS_Store
 btree.idx
+.stignore
diff --git a/src/btree.rs b/src/btree.rs
index 354d7d9..ade0036 100644
--- a/src/btree.rs
+++ b/src/btree.rs
@@ -1,7 +1,7 @@
+use crate::config::MAX_KEYS;
 use crate::node::*;
 use crate::record::Record;
 use crate::storage::Storage;
-const MAX_KEYS: usize = 4;
 
 pub struct BPlusTree<S> {
     storage: S,
diff --git a/src/config.rs b/src/config.rs
index 376009a..5bc575d 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -1 +1,2 @@
 pub const DEGREE: usize = 2;
+pub const MAX_KEYS: usize = 4;