diff --git a/docs/Project.toml b/docs/Project.toml
index 3764bfdd8..1bd4defaa 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -32,6 +32,7 @@ DataInterpolations = "6, 7, 8, 9.0"
 Documenter = "1"
 DocumenterCitations = "1"
 DocumenterInterLinks = "1"
+FFTW = "1.10.0"
 JLD2 = "0.6"
 LIBSVM = "0.8"
 LinearSolve = "4.2, 5"