diff --git a/OpenSSL/test/test_rand.py b/OpenSSL/test/test_rand.py
index 8a3c5fe..ffbb731 100644
--- a/OpenSSL/test/test_rand.py
+++ b/OpenSSL/test/test_rand.py
@@ -23,7 +23,14 @@
         self.assertRaises(TypeError, rand.bytes, None)
         self.assertRaises(TypeError, rand.bytes, 3, None)
 
-    # XXX Test failure of the malloc() in rand_bytes.
+
+    def test_insufficientMemory(self):
+        """
+        :py:obj:`OpenSSL.rand.bytes` raises :py:obj:`MemoryError` if more bytes
+        are requested than will fit in memory.
+        """
+        self.assertRaises(MemoryError, rand.bytes, 1024 * 1024 * 1024 * 1024)
+
 
     def test_bytes(self):
         """
diff --git a/OpenSSL/test/util.py b/OpenSSL/test/util.py
index 31242ce..a1a0cd9 100644
--- a/OpenSSL/test/util.py
+++ b/OpenSSL/test/util.py
@@ -14,7 +14,8 @@
 from unittest import TestCase
 import sys
 
-from OpenSSL.crypto import Error, _exception_from_error_queue
+from OpenSSL._util import exception_from_error_queue
+from OpenSSL.crypto import Error
 
 import memdbg
 
@@ -167,7 +168,7 @@
                 elif os.path.exists(temp):
                     os.unlink(temp)
         try:
-            _exception_from_error_queue()
+            exception_from_error_queue(Error)
         except Error:
             e = sys.exc_info()[1]
             if e.args != ([],):