diff --git a/docs/Lexicon.rst b/docs/Lexicon.rst
index 11f1341f5cb..fccfd5f85d8 100644
--- a/docs/Lexicon.rst
+++ b/docs/Lexicon.rst
@@ -50,7 +50,7 @@ C
     Common Subexpression Elimination. An optimization that removes common
     subexpression compuation. For example ``(a+b)*(a+b)`` has two subexpressions
     that are the same: ``(a+b)``. This optimization would perform the addition
-    only once and then perform the multiply (but only if it's compulationally
+    only once and then perform the multiply (but only if it's computationally
     correct/safe).
 
 D