diff --git a/src/owl/fftpack/owl_fft_d.mli b/src/owl/fftpack/owl_fft_d.mli
index d4fe082e3..093791d42 100644
--- a/src/owl/fftpack/owl_fft_d.mli
+++ b/src/owl/fftpack/owl_fft_d.mli
@@ -13,6 +13,13 @@ val fft
   -> (Complex.t, complex64_elt) Owl_dense_ndarray_generic.t
   -> (Complex.t, complex64_elt) Owl_dense_ndarray_generic.t
 
+val ifft
+  :  ?axis:int
+  -> ?norm:int
+  -> ?nthreads:int
+  -> (Complex.t, complex64_elt) Owl_dense_ndarray_generic.t
+  -> (Complex.t, complex64_elt) Owl_dense_ndarray_generic.t
+
 val rfft
   :  ?axis:int
   -> ?norm:int
diff --git a/src/owl/fftpack/owl_fft_s.mli b/src/owl/fftpack/owl_fft_s.mli
index 2a98138ce..aa4b0a643 100644
--- a/src/owl/fftpack/owl_fft_s.mli
+++ b/src/owl/fftpack/owl_fft_s.mli
@@ -13,6 +13,13 @@ val fft
   -> (Complex.t, complex32_elt) Owl_dense_ndarray_generic.t
   -> (Complex.t, complex32_elt) Owl_dense_ndarray_generic.t
 
+val ifft
+  :  ?axis:int
+  -> ?norm:int
+  -> ?nthreads:int
+  -> (Complex.t, complex32_elt) Owl_dense_ndarray_generic.t
+  -> (Complex.t, complex32_elt) Owl_dense_ndarray_generic.t
+
 val rfft
   :  ?axis:int
   -> ?norm:int