diff --git a/doc/1A_on_performance.qbk b/doc/1A_on_performance.qbk
index 968b18f..f254f09 100644
--- a/doc/1A_on_performance.qbk
+++ b/doc/1A_on_performance.qbk
@@ -86,7 +86,7 @@ Which gives us the following layout (and smaller total size):
 
 [$images/opt_align3.png]
 
-Sometimes it requires detailed consideration what data we make optional. In our case above, if we determine that both minimum and maximum value can be provided or not provided together, but one is never provided without the other, we can make only one optional memebr:
+Sometimes it requires detailed consideration what data we make optional. In our case above, if we determine that both minimum and maximum value can be provided or not provided together, but one is never provided without the other, we can make only one optional member:
 
   struct Limits
   {
diff --git a/doc/html/boost_optional/tutorial/performance_considerations.html b/doc/html/boost_optional/tutorial/performance_considerations.html
index 975a738..f6e7fb4 100644
--- a/doc/html/boost_optional/tutorial/performance_considerations.html
+++ b/doc/html/boost_optional/tutorial/performance_considerations.html
@@ -165,7 +165,7 @@
         Sometimes it requires detailed consideration what data we make optional.
         In our case above, if we determine that both minimum and maximum value can
         be provided or not provided together, but one is never provided without the
-        other, we can make only one optional memebr:
+        other, we can make only one optional member:
       </p>
 <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Limits</span>
 <span class="special">{</span>