diff --git a/lib/ft4/gen_ft4wave.f90 b/lib/ft4/gen_ft4wave.f90
index aa4174645..410e83401 100644
--- a/lib/ft4/gen_ft4wave.f90
+++ b/lib/ft4/gen_ft4wave.f90
@@ -35,7 +35,7 @@ subroutine gen_ft4wave(itone,nsym,nsps,fsample,f0,cwave,wave,icmplx,nwave)
   phi=0.0
   dphi = dphi + twopi*f0*dt                          !Shift frequency up by f0
   wave=0.
-  cwave=0.
+  if(icmplx.eq.1) cwave=0.
   k=0
   do j=0,nwave-1
      k=k+1