diff --git a/projects/cifuzz-example/Dockerfile b/projects/cifuzz-example/Dockerfile
index af1fd051f..2eddc64c4 100644
--- a/projects/cifuzz-example/Dockerfile
+++ b/projects/cifuzz-example/Dockerfile
@@ -19,4 +19,5 @@ RUN apt-get update && apt-get install -y make
 
 RUN git clone https://github.com/jonathanmetzman/cifuzz-example.git
 WORKDIR cifuzz-example
+RUN echo "hi" > untracked-file
 COPY build.sh $SRC/
diff --git a/projects/cifuzz-example/build.sh b/projects/cifuzz-example/build.sh
index 57aa20826..54e56e79f 100755
--- a/projects/cifuzz-example/build.sh
+++ b/projects/cifuzz-example/build.sh
@@ -15,8 +15,7 @@
 #
 ################################################################################
 
-echo $PWD
-ls .
+cat untracked-file  # Ensure CIFuzz doesn't junk untracked files.
 make clean  # Not strictly necessary, since we are building in a fresh dir.
 make -j$(nproc) all    # Build the fuzz targets.
 # make -j$(nproc) check  # Sanity check, not strictly required, but nice to have.