diff --git a/guacamole-docker/bin/build-guacamole.sh b/guacamole-docker/bin/build-guacamole.sh
index a5f08bbd1..d3f6741ac 100755
--- a/guacamole-docker/bin/build-guacamole.sh
+++ b/guacamole-docker/bin/build-guacamole.sh
@@ -60,6 +60,11 @@ mkdir -p "$DESTINATION"
 
 cd "$BUILD_DIR"
 
+# Required for build leveraging PhantomJS for unit testing (without this, the
+# build fails with "libssl_conf.so: cannot open shared object file: No such
+# file or directory")
+export OPENSSL_CONF=/etc/ssl
+
 if [ -z "$BUILD_PROFILE" ]; then
     mvn package
 else