diff --git a/opm/autodiff/SimulatorFullyImplicitBlackoilOutput.hpp b/opm/autodiff/SimulatorFullyImplicitBlackoilOutput.hpp
index 2becfdd38..b8b524094 100644
--- a/opm/autodiff/SimulatorFullyImplicitBlackoilOutput.hpp
+++ b/opm/autodiff/SimulatorFullyImplicitBlackoilOutput.hpp
@@ -277,7 +277,7 @@ namespace Opm
         /** \brief Whether this process does write to disk */
         bool isIORank () const
         {
-            parallelOutput_->isIORank();
+            return parallelOutput_->isIORank();
         }
 
         void restore(SimulatorTimerInterface& timer,