diff --git a/docker/master-java/Dockerfile b/docker/master-java/Dockerfile
index dcd8503f4..05a2640f8 100644
--- a/docker/master-java/Dockerfile
+++ b/docker/master-java/Dockerfile
@@ -54,9 +54,8 @@ RUN eval $(opam env) && \
     SKIP_SUBMODULES=true ./autogen.sh && \
     ./configure --disable-c-analyzers
 
-# Install Infer
-ENV INFER_HOME /infer/infer
-ENV PATH ${INFER_HOME}/bin:${PATH}
+# "Install" Infer. The tutorial assumes /infer-host is the working copy of infer so let's put it in the PATH too.
+ENV PATH /infer-host/infer/bin:/infer/bin:$PATH
 
 # build in non-optimized mode by default to speed up build times
 ENV BUILD_MODE=default
@@ -66,3 +65,10 @@ ENV IGNOREEOF=9
 
 # should be moved earlier
 ENV INFER_OPAM_SWITCH=4.07.1
+
+# export `opam env`
+ENV OPAM_SWITCH_PREFIX=/root/.opam/4.07.1
+ENV CAML_LD_LIBRARY_PATH=/root/.opam/4.07.1/lib/stublibs:/root/.opam/4.07.1/lib/ocaml/stublibs:/root/.opam/4.07.1/lib/ocaml
+ENV OCAML_TOPLEVEL_PATH=/root/.opam/4.07.1/lib/toplevel
+ENV MANPATH=$MANPATH:/root/.opam/4.07.1/man
+ENV PATH=/root/.opam/4.07.1/bin:$PATH
diff --git a/infer/src/labs/README.md b/infer/src/labs/README.md
index 9589b1d88..1d624bb26 100644
--- a/infer/src/labs/README.md
+++ b/infer/src/labs/README.md
@@ -14,13 +14,13 @@ Using Docker is the fastest way: you do not need to clone the Infer repository a
 
 2. Run the infer Docker image with `docker run -it -v $HOME/infer-docker:/infer-host infer/infer:infer-latest-java-dev /bin/bash`. This will give you a prompt *inside the Docker image*. Do not close that terminal for the duration of the lab.
 
-3. Within Docker, pull the latest version of infer, copy the /infer directory to your mount point, then set up the opam environment for OCaml:
+3. Within Docker, pull the latest version of infer, copy the /infer directory to your mount point, then fully build infer once:
 
 ```shell
 cd /infer
 git pull
 cp -av /infer/. /infer-host
-eval $(opam env)
+make -C /infer-host -j 4
 ```
 
 4. Outside Docker, you will likely need to change the permissions of `$HOME/infer-docker` to make the files editable by your user: `sudo chown $USER -R $HOME/infer-docker`.
@@ -37,10 +37,10 @@ See [CONTRIBUTING.md](https://github.com/facebook/infer/blob/master/CONTRIBUTING
 
 ## (1) Warm up: running, testing, and debugging Infer
 
-(a) Change to the test directory (`cd infer/tests/codetoanalyze/java/lab`) and run infer:
+(a) Change to the test directory (`cd infer/tests/codetoanalyze/java/lab`) and run infer in its default configuration:
 
 ```
-infer --resource-leak-only -- javac Leaks.java
+infer -- javac Leaks.java
 ```
 
 Infer should report 7 resource leaks. These reports come from the separation logic based biabduction analysis.
@@ -83,7 +83,7 @@ Finally, look again at the HTML debug output of infer on [Leaks.java](https://gi
 
 ```OCaml
   let last_loc = Procdesc.Node.get_loc (Procdesc.get_exit_node proc_data.pdesc) in
-  let message = F.asprintf "Leaked %d resource(s)" ResourceLeakDomain.pp leak_count in
+  let message = F.asprintf "Leaked %a resource(s)" ResourceLeakDomain.pp post in
   Reporting.log_error summary ~loc:last_loc IssueType.resource_leak message
 ```