diff --git a/nipype/interfaces/petpvc.py b/nipype/interfaces/petpvc.py
index c73b408bf3..63a0a8ed83 100644
--- a/nipype/interfaces/petpvc.py
+++ b/nipype/interfaces/petpvc.py
@@ -56,7 +56,7 @@ class PETPVCInputSpec(CommandLineInputSpec):
         argstr="-a %.4f")
     stop_crit = traits.Float(
         desc="Stopping criterion", default_value=0.01, usedefault=True,
-        argstr="-a %.4f")
+        argstr="-s %.4f")
 
 
 class PETPVCOutputSpec(TraitedSpec):
diff --git a/nipype/interfaces/tests/test_auto_PETPVC.py b/nipype/interfaces/tests/test_auto_PETPVC.py
index 60f5b29826..de7c1fa272 100644
--- a/nipype/interfaces/tests/test_auto_PETPVC.py
+++ b/nipype/interfaces/tests/test_auto_PETPVC.py
@@ -59,7 +59,7 @@ def test_PETPVC_inputs():
             mandatory=True,
         ),
         stop_crit=dict(
-            argstr='-a %.4f',
+            argstr='-s %.4f',
             usedefault=True,
         ),
     )