diff --git a/book/index.asc b/book/index.asc
deleted file mode 100644
index 9b0c1cfae..000000000
--- a/book/index.asc
+++ /dev/null
@@ -1 +0,0 @@
-== Index
diff --git a/index.asc b/index.asc
index 2df4a6b13..9618359ad 100644
--- a/index.asc
+++ b/index.asc
@@ -1,3 +1,3 @@
 [#index]
 [index]
-= Index
+== Index
diff --git a/progit.asc b/progit.asc
index 26e41bab3..9774d00c1 100644
--- a/progit.asc
+++ b/progit.asc
@@ -46,4 +46,4 @@ include::B-embedding-git-in-your-applications.asc[]
 
 include::C-git-commands.asc[]
 
-ifndef::ebook-format[include::index.asc[]]
+ifdef::backend-pdf[include::index.asc[]]