diff --git a/vm/src/builtins.rs b/vm/src/builtins.rs
index 0ac6946a7..a6a041a00 100644
--- a/vm/src/builtins.rs
+++ b/vm/src/builtins.rs
@@ -64,13 +64,15 @@ fn builtin_ascii(obj: PyObjectRef, vm: &VirtualMachine) -> PyResult<String> {
     let mut ascii = String::new();
     for c in repr.value.chars() {
         if c.is_ascii() {
-            ascii.push(c);
-        } else if (c as i64) < 0x10000 {
-            let hex = format!("\\u{:04x}", c as i64);
-            ascii.push_str(&hex);
+            ascii.push(c)
         } else {
-            let hex = format!("\\U{:08x}", c as i64);
-            ascii.push_str(&hex);
+            let c = c as i64;
+            let hex = if c < 0x10000 {
+                format!("\\u{:04x}", c)
+            } else {
+                format!("\\U{:08x}", c)
+            };
+            ascii.push_str(&hex)
         }
     }
     Ok(ascii)