diff --git a/testing/conftest.py b/testing/conftest.py
index 204c4490e..e91a64e89 100644
--- a/testing/conftest.py
+++ b/testing/conftest.py
@@ -4,48 +4,71 @@ import sys
 pytest_plugins = "pytester",
 
 import os, py
-pid = os.getpid()
+
+class LsofFdLeakChecker(object):
+    def get_open_files(self):
+        out = self._exec_lsof()
+        open_files = self._parse_lsof_output(out)
+        return open_files
+
+    def _exec_lsof(self):
+        pid = os.getpid()
+        return py.process.cmdexec("lsof -Ffn0 -p %d" % pid)
+
+    def _parse_lsof_output(self, out):
+        def isopen(line):
+            return line.startswith('f') and (
+                "deleted" not in line and 'mem' not in line and "txt" not in line and 'cwd' not in line)
+
+        open_files = []
+
+        for line in out.split("\n"):
+            if isopen(line):
+                fields = line.split('\0')
+                fd = fields[0][1:]
+                filename = fields[1][1:]
+                if filename.startswith('/'):
+                    open_files.append((fd, filename))
+
+        return open_files
+
 
 def pytest_addoption(parser):
     parser.addoption('--lsof',
            action="store_true", dest="lsof", default=False,
            help=("run FD checks if lsof is available"))
 
-def pytest_configure(config):
+def pytest_runtest_setup(item):
+    config = item.config
     config._basedir = py.path.local()
     if config.getvalue("lsof"):
         try:
-            out = py.process.cmdexec("lsof -p %d" % pid)
+            config._fd_leak_checker = LsofFdLeakChecker()
+            config._openfiles = config._fd_leak_checker.get_open_files()
         except py.process.cmdexec.Error:
             pass
-        else:
-            config._numfiles = len(getopenfiles(out))
 
 #def pytest_report_header():
 #    return "pid: %s" % os.getpid()
 
-def getopenfiles(out):
-    def isopen(line):
-        return ("REG" in line or "CHR" in line) and (
-            "deleted" not in line and 'mem' not in line and "txt" not in line)
-    return [x for x in out.split("\n") if isopen(x)]
-
 def check_open_files(config):
-    out2 = py.process.cmdexec("lsof -p %d" % pid)
-    lines2 = getopenfiles(out2)
-    if len(lines2) > config._numfiles + 3:
+    lines2 = config._fd_leak_checker.get_open_files()
+    new_fds = set([t[0] for t in lines2]) - set([t[0] for t in config._openfiles])
+    open_files = [t for t in lines2 if t[0] in new_fds]
+    if open_files:
         error = []
-        error.append("***** %s FD leackage detected" %
-    (len(lines2)-config._numfiles))
-        error.extend(lines2)
+        error.append("***** %s FD leackage detected" % len(open_files))
+        error.extend([str(f) for f in open_files])
+        error.append("*** Before:")
+        error.extend([str(f) for f in config._openfiles])
+        error.append("*** After:")
+        error.extend([str(f) for f in lines2])
         error.append(error[0])
-        # update numfile so that the overall test run continuess
-        config._numfiles = len(lines2)
         raise AssertionError("\n".join(error))
 
 def pytest_runtest_teardown(item, __multicall__):
     item.config._basedir.chdir()
-    if hasattr(item.config, '_numfiles'):
+    if hasattr(item.config, '_openfiles'):
         x = __multicall__.execute()
         check_open_files(item.config)
         return x