diff --git a/docker/dev.Dockerfile b/docker/dev.Dockerfile
index ce7e137..fe61ee1 100644
--- a/docker/dev.Dockerfile
+++ b/docker/dev.Dockerfile
@@ -49,14 +49,16 @@ ENV LANG=en_US.UTF-8
 ENV LANGUAGE=en_US:en
 ENV LC_ALL=en_US.UTF-8
 
-# Create app directory and copy the Elixir projects into it.
 WORKDIR /app
-COPY . ./
 
+COPY mix.exs mix.lock ./
 # Install Elixir deps
-# RUN mix archive.install github hexpm/hex branch latest
+# NOTE: this has to be before the bulk copy to ensure that deps are cached
 RUN MIX_ENV=dev mix deps.get && MIX_ENV=dev mix deps.compile
 RUN MIX_ENV=test mix deps.get && MIX_ENV=test mix deps.compile
+
+COPY . ./
+
 # Gives us iex shell history
 ENV ERL_AFLAGS="-kernel shell_history enabled"