diff --git a/optional_requirements.txt b/optional_requirements.txt
index 5cbdfbb0f544b621ac7269f8c3398e65f5fe9449..aad48e7d087f2717a6f42483fc95805d3e763fd3 100644
--- a/optional_requirements.txt
+++ b/optional_requirements.txt
@@ -3,4 +3,5 @@ lalsuite
 gwpy
 theano
 plotly
+tables
 pyfftw
diff --git a/requirements.txt b/requirements.txt
index 4c80f78a58f55ca3ba6b373ff37f694a72525eab..3f13fb51c46eb5797945ed80585e94e67b686533 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -9,4 +9,3 @@ mock
 dill
 tqdm
 h5py
-tables