diff --git a/website/source/docs/extend/post-processor.html.markdown b/website/source/docs/extend/post-processor.html.markdown
index f506dc80c..8148a4a0e 100644
--- a/website/source/docs/extend/post-processor.html.markdown
+++ b/website/source/docs/extend/post-processor.html.markdown
@@ -38,7 +38,7 @@ what each method should do.
 <pre class="prettyprint">
 type PostProcessor interface {
 	Configure(interface{}) error
-	PostProcess(Artifact) (Artifact, error)
+	PostProcess(Ui, Artifact) (Artifact, error)
 }
 </pre>
 
diff --git a/website/source/docs/extend/provisioner.html.markdown b/website/source/docs/extend/provisioner.html.markdown
index 6cacbdabb..bf6628b87 100644
--- a/website/source/docs/extend/provisioner.html.markdown
+++ b/website/source/docs/extend/provisioner.html.markdown
@@ -33,7 +33,7 @@ what each method should do.
 <pre class="prettyprint">
 type Provisioner interface {
 	Prepare(...interface{}) error
-	Provision(Ui, Communicator)
+	Provision(Ui, Communicator) error
 }
 </pre>