diff --git a/src/job/job.cpp b/src/job/job.cpp
index c202aad2..92b736fa 100644
--- a/src/job/job.cpp
+++ b/src/job/job.cpp
@@ -44,7 +44,7 @@ job::~job()
 void job::check_job_dirs()
 {
 	// initialize default working directory inside sandbox
-	working_path_ = fs::path("/box");
+	sandbox_working_path_ = fs::path("/box");
 
 	if (!fs::exists(temporary_directory_)) {
 		throw job_exception("Working directory not exists");
@@ -135,7 +135,8 @@ void job::build_job()
 
 			// check relativeness of working directory
 			if (!helpers::check_relative(fs::path(sandbox->working_directory))) {
-				throw job_exception("Given working directory for task '" + task_meta->task_id + "' is not relative");
+				throw job_exception(
+					"Given working directory for task '" + task_meta->task_id + "' is not relative or contains '..'");
 			}
 
 			// go through variables parsing
@@ -160,7 +161,7 @@ void job::build_job()
 				logger_,
 				temporary_directory_.string(),
 				source_path_,
-				working_path_};
+				sandbox_working_path_};
 
 			task = factory_->create_sandboxed_task(data);
 
@@ -440,7 +441,7 @@ void job::prepare_job_vars()
 		{"JOB_ID", job_meta_->job_id},
 		{"SOURCE_DIR", source_path_.string()},
 		{"RESULT_DIR", result_path_.string()},
-		{"EVAL_DIR", working_path_.string()},
+		{"EVAL_DIR", sandbox_working_path_.string()},
 		{"TEMP_DIR", fs::temp_directory_path().string()},
 		{"JUDGES_DIR", fs::path("/usr/bin").string()}};
 
diff --git a/src/job/job.h b/src/job/job.h
index afcded87..ebd9cb1e 100644
--- a/src/job/job.h
+++ b/src/job/job.h
@@ -141,7 +141,7 @@ class job
 	/** Directory where results and log of job are stored. */
 	fs::path result_path_;
 	/** Directory inside sandbox which should be bound as the working one. */
-	fs::path working_path_;
+	fs::path sandbox_working_path_;
 	/** Factory for creating tasks. */
 	std::shared_ptr<task_factory_interface> factory_;
 	/** Progress callback which is called on some important points */
diff --git a/src/tasks/create_params.h b/src/tasks/create_params.h
index 099cd752..8271ec69 100644
--- a/src/tasks/create_params.h
+++ b/src/tasks/create_params.h
@@ -25,7 +25,7 @@ struct create_params {
 	/** directory where source files given by users are located */
 	fs::path source_path;
 	/** working directory which points inside sandbox */
-	fs::path working_path;
+	fs::path sandbox_working_path;
 };
 
 
diff --git a/src/tasks/external_task.cpp b/src/tasks/external_task.cpp
index e94d3400..d207371f 100644
--- a/src/tasks/external_task.cpp
+++ b/src/tasks/external_task.cpp
@@ -13,7 +13,7 @@ namespace fs = boost::filesystem;
 external_task::external_task(const create_params &data)
 	: task_base(data.id, data.task_meta), worker_config_(data.worker_conf), sandbox_(nullptr),
 	  sandbox_config_(data.task_meta->sandbox), limits_(data.limits), logger_(data.logger), temp_dir_(data.temp_dir),
-	  evaluation_dir_(data.source_path), working_dir_(data.working_path)
+	  evaluation_dir_(data.source_path), sandbox_working_dir_(data.sandbox_working_path)
 {
 	if (worker_config_ == nullptr) {
 		throw task_exception("No worker configuration provided.");
@@ -29,7 +29,7 @@ external_task::external_task(const create_params &data)
 
 	if (!sandbox_config_->working_directory.empty()) {
 		if (!helpers::check_relative(sandbox_config_->working_directory)) {
-			throw task_exception("Given working directory in sandbox config is not relative");
+			throw task_exception("Given working directory in sandbox config is not relative or contains '..'");
 		}
 
 		evaluation_dir_ = fs::path(data.source_path) / sandbox_config_->working_directory;
@@ -124,7 +124,7 @@ void external_task::results_output_init()
 		if (sandbox_config_->std_output == "") {
 			remove_stdout_ = true;
 			std::string stdout_file = task_meta_->task_id + "." + random + ".output.stdout";
-			sandbox_config_->std_output = (working_dir_ / fs::path(stdout_file)).string();
+			sandbox_config_->std_output = (sandbox_working_dir_ / fs::path(stdout_file)).string();
 		}
 	}
 
@@ -133,7 +133,7 @@ void external_task::results_output_init()
 		if (sandbox_config_->std_error == "") {
 			remove_stderr_ = true;
 			std::string stderr_file = task_meta_->task_id + "." + random + ".output.stderr";
-			sandbox_config_->std_error = (working_dir_ / fs::path(stderr_file)).string();
+			sandbox_config_->std_error = (sandbox_working_dir_ / fs::path(stderr_file)).string();
 		}
 	}
 }
diff --git a/src/tasks/external_task.h b/src/tasks/external_task.h
index 98aa6015..191b4aab 100644
--- a/src/tasks/external_task.h
+++ b/src/tasks/external_task.h
@@ -101,7 +101,7 @@ class external_task : public task_base
 	/** Directory outside sandbox where task will be executed */
 	fs::path evaluation_dir_;
 	/** Directory binded to the sandbox as default working dir */
-	fs::path working_dir_;
+	fs::path sandbox_working_dir_;
 	/** After execution delete stdout file produced by sandbox */
 	bool remove_stdout_ = false;
 	/** After execution delete stderr file produced by sandbox */