diff --git a/content/complex_integration.html b/content/complex_integration.html
index 8dd9769..271c63d 100644
--- a/content/complex_integration.html
+++ b/content/complex_integration.html
@@ -414,7 +414,7 @@ <h2>Properties</h2>
                     \end{eqnarray*}
                 </div>
                 <p>
-                    In we use the substition $\tau = -t$ in the last integral, then
+                    In we use the substitution $\tau = -t$ in the last integral, then
                 </p>
                 <div class="scroll-wrapper">
                     \begin{eqnarray*}