diff --git a/opm/autodiff/SimulatorBase_impl.hpp b/opm/autodiff/SimulatorBase_impl.hpp
index 3d39daa3b..d155d769f 100644
--- a/opm/autodiff/SimulatorBase_impl.hpp
+++ b/opm/autodiff/SimulatorBase_impl.hpp
@@ -222,7 +222,10 @@ namespace Opm
             // Increment timer, remember well state.
             ++timer;
             prev_well_state = well_state;
-            asImpl().computeWellPotentials(timer.currentStepNum(), wells, state, well_state, well_potentials);
+            // Compute Well potentials (only used to determine default guide rates for group controlled wells)
+            if (schedule->numGroups() > 0 ) {
+                asImpl().computeWellPotentials(timer.currentStepNum(), wells, state, well_state, well_potentials);
+            }
         }
 
         // Write final simulation state.
@@ -395,31 +398,28 @@ namespace Opm
         const int nw = wells->number_of_wells;
         const int np = wells->number_of_phases;
         well_potentials.clear();
-        well_potentials.resize(nw*np,0.0);
-        if( ! xw.wellMap().empty() )
-        {
-            for (int w = 0; w < nw; ++w) {
-                for (int perf = wells->well_connpos[w]; perf < wells->well_connpos[w + 1]; ++perf) {
-                    const double well_cell_pressure = x.pressure()[wells->well_cells[perf]];
-                    const double drawdown_used = well_cell_pressure - xw.perfPress()[perf];
-                    const WellControls* ctrl = wells->ctrls[w];
-                    const int nwc = well_controls_get_num(ctrl);
-                    //Loop over all controls until we find a BHP control
-                    //that specifies what we need...
-                    double bhp = 0.0;
-                    for (int ctrl_index=0; ctrl_index < nwc; ++ctrl_index) {
-                        if (well_controls_iget_type(ctrl, ctrl_index) == BHP) {
-                            bhp = well_controls_iget_target(ctrl, ctrl_index);
-                        }
-                        // TODO: do something for thp;
+        well_potentials.resize(nw*np,0.0);       
+        for (int w = 0; w < nw; ++w) {
+            for (int perf = wells->well_connpos[w]; perf < wells->well_connpos[w + 1]; ++perf) {
+                const double well_cell_pressure = x.pressure()[wells->well_cells[perf]];
+                const double drawdown_used = well_cell_pressure - xw.perfPress()[perf];
+                const WellControls* ctrl = wells->ctrls[w];
+                const int nwc = well_controls_get_num(ctrl);
+                //Loop over all controls until we find a BHP control
+                //that specifies what we need...
+                double bhp = 0.0;
+                for (int ctrl_index=0; ctrl_index < nwc; ++ctrl_index) {
+                    if (well_controls_iget_type(ctrl, ctrl_index) == BHP) {
+                        bhp = well_controls_iget_target(ctrl, ctrl_index);
                     }
-                    // Calculate the pressure difference in the well perforation
-                    const double dp = xw.perfPress()[perf] - xw.bhp()[w];
-                    const double drawdown_maximum = well_cell_pressure - (bhp + dp);
+                    // TODO: do something for thp;
+                }
+                // Calculate the pressure difference in the well perforation
+                const double dp = xw.perfPress()[perf] - xw.bhp()[w];
+                const double drawdown_maximum = well_cell_pressure - (bhp + dp);
 
-                    for (int phase = 0; phase < np; ++phase) {
-                        well_potentials[w*np + phase] += (drawdown_maximum / drawdown_used * xw.perfPhaseRates()[perf*np + phase]);
-                    }
+                for (int phase = 0; phase < np; ++phase) {
+                    well_potentials[w*np + phase] += (drawdown_maximum / drawdown_used * xw.perfPhaseRates()[perf*np + phase]);
                 }
             }
         }