diff --git a/modules/img/alg/src/fft.cc b/modules/img/alg/src/fft.cc
index 468bc4992e1ce344d2a69f6ef7e6c1db0bad9d13..61cc3199c645e37f8d17a9daab0b9fd8c286858d 100644
--- a/modules/img/alg/src/fft.cc
+++ b/modules/img/alg/src/fft.cc
@@ -268,7 +268,7 @@ ImageStateBasePtr FFTFnc::VisitState(const ImageStateImpl<T,D>& s) const
 }
 
 // force explicit instantiation to make intel compiler happy
-template ImageStateBasePtr FFTFnc::VisitState<float,FrequencyDomain>(const ImageStateImpl<float,FrequencyDomain>& ) const;
+template ImageStateBasePtr FFTFnc::VisitState<Real,FrequencyDomain>(const ImageStateImpl<Real,FrequencyDomain>& ) const;
 template ImageStateBasePtr FFTFnc::VisitState<unsigned short,SpatialDomain>(const ImageStateImpl<unsigned short,SpatialDomain>& ) const;
 
 }  //alg ns