--- a/liboctave/oct-fftw.h
+++ b/liboctave/oct-fftw.h
@@ -24,11 +24,16 @@
 #define octave_oct_fftw_h 1
 
 #include <cstddef>
+
+#if defined (HAVE_FFTW3_H)
 #include <fftw3.h>
+#endif
 
 #include "oct-cmplx.h"
 #include "dim-vector.h"
 
+#if defined (HAVE_FFTW)
+
 class
 OCTAVE_API
 octave_fftw_planner
@@ -292,6 +297,7 @@
 octave_fftw
 {
 public:
+
   static int fft (const double *in, Complex *out, size_t npts, 
 		  size_t nsamples = 1, octave_idx_type stride = 1, octave_idx_type dist = -1);
   static int fft (const Complex *in, Complex *out, size_t npts, 
@@ -319,13 +325,15 @@
 		     const dim_vector &);
 
 private:
-  octave_fftw ();
+  octave_fftw (void);
   octave_fftw (const octave_fftw&);
   octave_fftw& operator = (const octave_fftw&);
 };
 
 #endif
 
+#endif
+
 /*
 ;;; Local Variables: ***
 ;;; mode: C++ ***