diff --git a/src/KOKKOS/fftdata_kokkos.h b/src/KOKKOS/fftdata_kokkos.h
index 15dca33bcc..7f900002e5 100644
--- a/src/KOKKOS/fftdata_kokkos.h
+++ b/src/KOKKOS/fftdata_kokkos.h
@@ -12,30 +12,21 @@
    See the README file in the top-level LAMMPS directory.
 ------------------------------------------------------------------------- */
 
+// data types for 2d/3d FFTs
+
+#ifndef LMP_FFT_DATA_KOKKOS_H
+#define LMP_FFT_DATA_KOKKOS_H
+
 #include "kokkos_type.h"
 
 #ifndef MAX
 #define MAX(A,B) ((A) > (B) ? (A) : (B))
 #endif
 
-// data types for 2d/3d FFTs
-
-#ifndef LMP_FFT_DATA_KOKKOS_H
-#define LMP_FFT_DATA_KOKKOS_H
-
-#include "lmpfftsettings_kokkos.h"
+#include "lmpfftsettings.h"
 
 // -------------------------------------------------------------------------
 
-// Data types for single-precision complex
-
-#if FFT_PRECISION == 1
-#elif FFT_PRECISION == 2
-#else
-#error "FFT_PRECISION needs to be either 1 (=single) or 2 (=double)"
-#endif
-
-
 // with KOKKOS in CUDA or HIP mode we can only have
 // CUFFT/HIPFFT or KISSFFT, thus undefine all other
 // FFTs here, since they may be valid in fft3d.cpp
diff --git a/src/KOKKOS/lmpfftsettings_kokkos.h b/src/KOKKOS/lmpfftsettings_kokkos.h
deleted file mode 100644
index 6cea9bb63a..0000000000
--- a/src/KOKKOS/lmpfftsettings_kokkos.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/* -*- c++ -*- ----------------------------------------------------------
-   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
-   https://www.lammps.org/, Sandia National Laboratories
-   LAMMPS development team: developers@lammps.org
-
-   Copyright (2003) Sandia Corporation.  Under the terms of Contract
-   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
-   certain rights in this software.  This software is distributed under
-   the GNU General Public License.
-
-   See the README file in the top-level LAMMPS directory.
-------------------------------------------------------------------------- */
-
-// common FFT library related defines and compilation settings
-
-#ifndef LMP_FFT_KOKKOS_SETTINGS_H
-#define LMP_FFT_KOKKOS_SETTINGS_H
-
-#include "lmpfftsettings.h"
-
-// if user set FFTW, it means FFTW3
-
-#ifdef FFT_KOKKOS_FFTW
-#ifndef FFT_KOKKOS_FFTW3
-#define FFT_KOKKOS_FFTW3
-#endif
-#endif
-
-// set strings for library info output
-
-#if defined(FFT_KOKKOS_FFTW3)
-#define LMP_FFT_KOKKOS_LIB "FFTW3"
-#elif defined(FFT_KOKKOS_MKL)
-#define LMP_FFT_KOKKOS_LIB "MKL FFT"
-#elif defined(FFT_KOKKOS_CUFFT)
-#define LMP_FFT_KOKKOS_LIB "cuFFT"
-#elif defined(FFT_KOKKOS_HIPFFT)
-#define LMP_FFT_KOKKOS_LIB "hipFFT"
-#else
-#define LMP_FFT_KOKKOS_LIB "KISS FFT"
-#endif
-
-#endif
diff --git a/src/lmpfftsettings.h b/src/lmpfftsettings.h
index 7fad0de8c7..426726440e 100644
--- a/src/lmpfftsettings.h
+++ b/src/lmpfftsettings.h
@@ -16,7 +16,7 @@
 #ifndef LMP_FFT_SETTINGS_H
 #define LMP_FFT_SETTINGS_H
 
-// if user set FFTW, it means FFTW3
+// if a user sets FFTW, it means FFTW3
 
 #ifdef FFT_FFTW
 #ifndef FFT_FFTW3
@@ -24,6 +24,14 @@
 #endif
 #endif
 
+#ifdef LMP_KOKKOS
+#ifdef FFT_KOKKOS_FFTW
+#ifndef FFT_KOKKOS_FFTW3
+#define FFT_KOKKOS_FFTW3
+#endif
+#endif
+#endif
+
 // set strings for library info output
 
 #if defined(FFT_FFTW3)
@@ -38,6 +46,20 @@
 #define LMP_FFT_LIB "KISS FFT"
 #endif
 
+#ifdef LMP_KOKKOS
+#if defined(FFT_KOKKOS_FFTW3)
+#define LMP_FFT_KOKKOS_LIB "FFTW3"
+#elif defined(FFT_KOKKOS_MKL)
+#define LMP_FFT_KOKKOS_LIB "MKL FFT"
+#elif defined(FFT_KOKKOS_CUFFT)
+#define LMP_FFT_KOKKOS_LIB "cuFFT"
+#elif defined(FFT_KOKKOS_HIPFFT)
+#define LMP_FFT_KOKKOS_LIB "hipFFT"
+#else
+#define LMP_FFT_KOKKOS_LIB "KISS FFT"
+#endif
+#endif
+
 #ifdef FFT_SINGLE
 typedef float FFT_SCALAR;
 #define FFT_PRECISION 1