diff --git a/HMC/Mobius2p1fEOFA_F1.cc b/HMC/Mobius2p1fEOFA_F1.cc
index 59160c1e..672c343a 100644
--- a/HMC/Mobius2p1fEOFA_F1.cc
+++ b/HMC/Mobius2p1fEOFA_F1.cc
@@ -30,7 +30,9 @@ directory
 /*  END LEGAL */
 #include <Grid/Grid.h>
 
+#ifdef GRID_DEFAULT_PRECISION_DOUBLE
 #define MIXED_PRECISION
+#endif
 
 namespace Grid{ 
   namespace QCD{
@@ -48,6 +50,8 @@ namespace Grid{
     typedef typename FermionOperatorD::FermionField FieldD;
     typedef typename FermionOperatorF::FermionField FieldF;
 
+    using OperatorFunction<FieldD>::operator();
+
     RealD   Tolerance;
     RealD   InnerTolerance; //Initial tolerance for inner CG. Defaults to Tolerance but can be changed
     Integer MaxInnerIterations;