diff --git a/2021/day12/day12_rs/src/main.rs b/2021/day12/day12_rs/src/main.rs
index 5a92c54..f4e81aa 100644
--- a/2021/day12/day12_rs/src/main.rs
+++ b/2021/day12/day12_rs/src/main.rs
@@ -45,10 +45,10 @@ fn main() {
             let p1 = parts.next().unwrap();
             let p2 = parts.next().unwrap();
 
-            if p2 != "start" {
+            if p1 != "end" && p2 != "start" {
                 map.entry(p1).or_default().insert(p2);
             }
-            if p2 != "end" {
+            if p2 != "end" && p1 != "start" {
                 map.entry(p2).or_default().insert(p1);
             }
             map