diff --git a/slides/containers/Advanced_Dockerfiles.md b/slides/containers/Advanced_Dockerfiles.md
index f581af8c..58cb1713 100644
--- a/slides/containers/Advanced_Dockerfiles.md
+++ b/slides/containers/Advanced_Dockerfiles.md
@@ -1,3 +1,6 @@
+
+class: title
+
 # Advanced Dockerfiles
 
 ![construction](images/title-advanced-dockerfiles.jpg)
diff --git a/slides/containers/Getting_Inside.md b/slides/containers/Getting_Inside.md
index 9f232f92..9167dfdc 100644
--- a/slides/containers/Getting_Inside.md
+++ b/slides/containers/Getting_Inside.md
@@ -1,3 +1,4 @@
+
 class: title
 
 # Getting inside a container
diff --git a/slides/containers/Installing_Docker.md b/slides/containers/Installing_Docker.md
index 41cfa90b..ced137d4 100644
--- a/slides/containers/Installing_Docker.md
+++ b/slides/containers/Installing_Docker.md
@@ -1,3 +1,4 @@
+
 class: title
 
 # Installing Docker
diff --git a/slides/containers/Training_Environment.md b/slides/containers/Training_Environment.md
index 2176cb59..45302a17 100644
--- a/slides/containers/Training_Environment.md
+++ b/slides/containers/Training_Environment.md
@@ -1,3 +1,4 @@
+
 class: title
 
 # Our training environment