diff --git a/docs/src/index.md b/docs/src/index.md
index 3f3de202..8f0f8c03 100644
--- a/docs/src/index.md
+++ b/docs/src/index.md
@@ -20,6 +20,6 @@ using Flux
 
 You'll also need a backend to run real training, if you don't have one already. Choose from [MXNet](https://github.com/dmlc/MXNet.jl) or [TensorFlow](https://github.com/malmaud/TensorFlow.jl) (MXNet is the recommended option if you're not sure):
 
-```
+```julia
 Pkg.add("MXNet") # or "TensorFlow"
 ```