diff --git a/src/main/tools/linux-sandbox-options.cc b/src/main/tools/linux-sandbox-options.cc
index b399b02..9f0039c 100644
--- a/src/main/tools/linux-sandbox-options.cc
+++ b/src/main/tools/linux-sandbox-options.cc
@@ -262,6 +262,11 @@
   }
 
   if (opt.working_dir.empty()) {
-    opt.working_dir = getcwd(nullptr, 0);
+    char *working_dir = getcwd(nullptr, 0);
+    if (working_dir == nullptr) {
+      DIE("getcwd");
+    }
+    opt.working_dir = working_dir;
+    free(working_dir);
   }
 }