--- a/src/util/tests/cache_test.cpp
+++ b/src/util/tests/cache_test.cpp
@@ -84,8 +84,8 @@ check_directories_created(void *mem_ctx,
 {
    bool sub_dirs_created = false;
 
-   char buf[PATH_MAX];
-   if (getcwd(buf, PATH_MAX)) {
+   char *buf = getcwd(NULL, 0);
+   if (buf) {
       char *full_path = ralloc_asprintf(mem_ctx, "%s%s", buf, ++cache_dir);
       struct stat sb;
       if (stat(full_path, &sb) != -1 && S_ISDIR(sb.st_mode))
--- a/src/util/tests/process_test.c
+++ b/src/util/tests/process_test.c
@@ -36,6 +36,10 @@
 #define PATH_MAX MAX_PATH
 #endif
 
+#if !defined(PATH_MAX) && defined(__GNU__)
+#define PATH_MAX (4096)
+#endif
+
 static bool error = false;
 
 static void