diff --git a/rust/0205-isomorphic-strings.rs b/rust/0205-isomorphic-strings.rs
index fd8382435..6f07885be 100644
--- a/rust/0205-isomorphic-strings.rs
+++ b/rust/0205-isomorphic-strings.rs
@@ -5,14 +5,17 @@ impl Solution {
         let (mut map_s_to_t, mut map_t_to_s) = (HashMap::new(), HashMap::new());
 
         for (c1, c2) in s.chars().zip(t.chars()) {
-            if (map_s_to_t.contains_key(&c1) && map_s_to_t.get(&c1) != Some(&c2))
-                || (map_t_to_s.contains_key(&c2) && map_t_to_s.get(&c2) != Some(&c1))
-            {
-                return false;
+            if let Some(w) = map_s_to_t.insert(c1, c2) {
+                if w != c2 {
+                    return false;
+                }
             }
 
-            map_s_to_t.insert(c1, c2);
-            map_t_to_s.insert(c2, c1);
+            if let Some(w) = map_t_to_s.insert(c2, c1) {
+                if w != c1 {
+                    return false;
+                }
+            }
         }
 
         true