diff --git a/proposals/simd/SIMD.md b/proposals/simd/SIMD.md
index 4f9e073f6..00e7838a4 100644
--- a/proposals/simd/SIMD.md
+++ b/proposals/simd/SIMD.md
@@ -300,7 +300,7 @@ def S.shuffle(a, b, s):
         if s[i] < S.lanes:
             result[i] = a[s[i]]
         else:
-            result[i] = b[s[i] - S.lanes
+            result[i] = b[s[i] - S.lanes]
     return result
 ```