diff --git a/contrib/fuzz/manifest.cc b/contrib/fuzz/manifest.cc
--- a/contrib/fuzz/manifest.cc
+++ b/contrib/fuzz/manifest.cc
@@ -31,6 +31,8 @@
 	strncpy(cpypath, pypath.c_str(), pypath.size());
 	setenv("PYTHONPATH", cpypath, 1);
 	setenv("PYTHONNOUSERSITE", "1", 1);
+	/* prevent Python from looking up users in the fuzz environment */
+	setenv("PYTHONUSERBASE", cpypath, 1);
 	Py_SetPythonHome(cpypath);
 	Py_InitializeEx(0);
 	return 0;