diff --git a/tests/test_waveform_grid.py b/tests/test_waveform_grid.py
index fe929994..fea7e9d2 100644
--- a/tests/test_waveform_grid.py
+++ b/tests/test_waveform_grid.py
@@ -159,6 +159,7 @@ def test_hyper_translation():
 
 
 def test_supertranslation_inverses():
+    np.random.seed(1234)
     w1 = samples.random_waveform_proportional_to_time(rotating=False)
     ell_max = 4
     for ellpp, mpp in sf.LM_range(0, ell_max):