diff --git a/src/libra_py/trpes.py b/src/libra_py/trpes.py
index 78241e4bf..163d2ef6b 100644
--- a/src/libra_py/trpes.py
+++ b/src/libra_py/trpes.py
@@ -22,6 +22,7 @@
 import h5py
 import matplotlib.pyplot as plt
 from matplotlib import cm
+import scipy.sparse as sp
 from scipy.optimize import curve_fit
 from matplotlib.ticker import FormatStrFormatter