diff --git a/src/protein/residue.py b/src/protein/residue.py
index 62bb23a..519d2fd 100644
--- a/src/protein/residue.py
+++ b/src/protein/residue.py
@@ -29,12 +29,12 @@ class Residue():
         self.name = name
 
         self.backbone = {
-            atoms: { "N": None, "CA": None, "C": None, "O": None },
-            phi: None,
-            psi: None
+            "atoms": { "N": None, "CA": None, "C": None, "O": None },
+            "phi": None,
+            "psi": None
         }
         
         self.sidechain = {
-            atoms: {},
-            chis: []
+            "atoms": {},
+            "chis": []
         }