diff --git a/src/fourier/fft/fftw_complex.hpp b/src/fourier/fft/fftw_complex.hpp
new file mode 100644
index 0000000..af5d445
--- /dev/null
+++ b/src/fourier/fft/fftw_complex.hpp
@@ -0,0 +1,42 @@
+#ifndef __COSMOTOOL_FFT_COMPLEX_HPP
+#define __COSMOTOOL_FFT_COMPLEX_HPP
+
+#include <complex>
+#include <fftw3.h>
+
+namespace CosmoTool
+{
+    template<typename T>
+    struct adapt_complex {
+    };
+
+    template<> struct adapt_complex<fftw_complex> {
+        typedef fftw_complex f_type;
+        typedef std::complex<double> cpp_complex;
+        
+        static inline cpp_complex *adapt(f_type *a) {
+            return reinterpret_cast<cpp_complex *>(a);
+        }
+    };
+    
+    template<> struct adapt_complex<fftwf_complex> {
+        typedef fftwf_complex f_type;
+        typedef std::complex<float> cpp_complex;
+        
+        static inline cpp_complex *adapt(f_type *a) {
+            return reinterpret_cast<cpp_complex *>(a);
+        }
+    };
+
+    template<> struct adapt_complex<fftwl_complex> {
+        typedef fftwl_complex f_type;
+        typedef std::complex<long double> cpp_complex;
+        
+        static inline cpp_complex *adapt(f_type *a) {
+            return reinterpret_cast<cpp_complex *>(a);
+        }
+    };
+
+}
+
+#endif
\ No newline at end of file