diff --git a/nipype/interfaces/base.py b/nipype/interfaces/base.py
index d60e8a2486..5221646f15 100644
--- a/nipype/interfaces/base.py
+++ b/nipype/interfaces/base.py
@@ -996,8 +996,9 @@ def run(self, **inputs):
             runtime = self._run_interface(runtime)
             outputs = self.aggregate_outputs(runtime)
             runtime.endTime = dt.isoformat(dt.utcnow())
-            runtime.duration = (parseutc(runtime.endTime) -
-                                parseutc(runtime.startTime)).total_seconds()
+            timediff = parseutc(runtime.endTime) - parseutc(runtime.startTime)
+            runtime.duration = timediff.days * 86400 + timediff.seconds + \
+                timediff.microseconds/100000.
             results = InterfaceResult(interface, runtime,
                                       inputs=self.inputs.get_traitsfree(),
                                       outputs=outputs)
@@ -1005,8 +1006,9 @@ def run(self, **inputs):
             results.provenance = prov_record
         except Exception, e:
             runtime.endTime = dt.isoformat(dt.utcnow())
-            runtime.duration = (parseutc(runtime.endTime) -
-                                parseutc(runtime.startTime)).total_seconds()
+            timediff = parseutc(runtime.endTime) - parseutc(runtime.startTime)
+            runtime.duration = timediff.days * 86400 + timediff.seconds + \
+                timediff.microseconds/100000.
             if len(e.args) == 0:
                 e.args = ("")