diff --git a/source/manuals/programming-languages/docker.html.md.erb b/source/manuals/programming-languages/docker.html.md.erb
index 438102b3..baf7077e 100644
--- a/source/manuals/programming-languages/docker.html.md.erb
+++ b/source/manuals/programming-languages/docker.html.md.erb
@@ -28,7 +28,7 @@ For example:
 
 ```
 # 3.9
-FROM alpine
+FROM alpine:3.9
 ```
 
 where: