diff --git a/scaling-functions.Rmd b/scaling-functions.Rmd
index 1927d43c..9a37b198 100644
--- a/scaling-functions.Rmd
+++ b/scaling-functions.Rmd
@@ -278,15 +278,15 @@ This doesn't make testing or debugging any easier, but it does reduce duplicated
 We could of course add `session` to the arguments of the function:
 
 ```{r}
-switch_page <- function(i) {
-  updateTabsetPanel(input = "wizard", selected = paste0("page_", i))
+switch_page <- function(i, session) {
+  updateTabsetPanel(session = session, input = "wizard", selected = paste0("page_", i))
 }
 
 server <- function(input, output, session) {
-  observeEvent(input$page_12, switch_page(2))
-  observeEvent(input$page_21, switch_page(1))
-  observeEvent(input$page_23, switch_page(3))
-  observeEvent(input$page_32, switch_page(2))
+  observeEvent(input$page_12, switch_page(2, session))
+  observeEvent(input$page_21, switch_page(1, session))
+  observeEvent(input$page_23, switch_page(3, session))
+  observeEvent(input$page_32, switch_page(2, session))
 }
 ```
 
diff --git a/scaling-modules.Rmd b/scaling-modules.Rmd
index 244a4516..edb6e31c 100644
--- a/scaling-modules.Rmd
+++ b/scaling-modules.Rmd
@@ -983,7 +983,7 @@ This is a principled limitation of the module system which we'll discuss in more
 
 Now let's use the wizard in a slightly more realistic app that has inputs and outputs, and yields Figure \@ref(fig:wizard-module).
 The main point to notice is that even though the pages are displayed by the module, their ids are controlled by the user of the module.
-It's the developer who creators the control who controls its name; it doesn't matter who ends up assembling the control for final display on the webpage.
+It's the developer who creates the control and controls its name; it doesn't matter who ends up assembling the control for final display on the webpage.
 
 ```{r}
 page1 <- tagList(
diff --git a/scaling-testing.Rmd b/scaling-testing.Rmd
index 2ada29e0..e167eae3 100644
--- a/scaling-testing.Rmd
+++ b/scaling-testing.Rmd
@@ -428,7 +428,7 @@ summaryServer <- function(id, var) {
 ```
 
 We'll use `testServer()` as above, but the call is a little different.
-As before the first argument is the server function (now the the module server), but now we also need to supply additional arguments in a list called `args`.
+As before the first argument is the server function (now the module server), but now we also need to supply additional arguments in a list called `args`.
 This takes a list of arguments to the module server (the `id` argument is optional; `testServer()` will fill it in automatically if omitted).
 Then we finish up with the code to run: