diff --git a/R/app.R b/R/app.R
index b1d8f17d7a..676db7c217 100644
--- a/R/app.R
+++ b/R/app.R
@@ -121,8 +121,10 @@ shinyAppDir <- function(appDir, options=list()) {
   appDir <- normalizePath(appDir, mustWork = TRUE)
 
   if (file.exists.ci(appDir, "server.R")) {
+    shinyOption(appFile = "server.R")
     shinyAppDir_serverR(appDir, options = options)
   } else if (file.exists.ci(appDir, "app.R")) {
+    shinyOption(appFile = "app.R")
     shinyAppDir_appR("app.R", appDir, options = options)
   } else {
     stop("App dir must contain either app.R or server.R.")
@@ -136,6 +138,7 @@ shinyAppFile <- function(appFile, options=list()) {
   appFile <- normalizePath(appFile, mustWork = TRUE)
   appDir <- dirname(appFile)
 
+  shinyOption(appFile = basename(appFile))
   shinyAppDir_appR(basename(appFile), appDir, options = options)
 }
 
diff --git a/R/showcase.R b/R/showcase.R
index c500287450..930482cd04 100644
--- a/R/showcase.R
+++ b/R/showcase.R
@@ -81,7 +81,7 @@ appMetadata <- function(desc) {
 navTabsHelper <- function(files, prefix = "") {
   lapply(files, function(file) {
     with(tags,
-      li(class=if (tolower(file) %in% c("app.r", "server.r")) "active" else "",
+      li(class=if (identical(file, getShinyOption("appFile"))) "active" else "",
          a(href=paste0("#", gsub("\\.|\\s+", "_", file), "_code"),
            "data-toggle"="tab", paste0(prefix, file)))
     )
@@ -106,8 +106,7 @@ tabContentHelper <- function(files, path, language) {
   lapply(files, function(file) {
     with(tags,
       div(class=paste0("tab-pane",
-                      # TODO: what if the app filename is something else?
-                      if (tolower(file) %in% c("app.r", "server.r")) " active"
+                      if (identical(file, getShinyOption("appFile"))) " active"
                       else ""),
           id=paste0(gsub("\\.|\\s+", "_", file), "_code"),
           pre(class="shiny-code",