diff --git a/mhkit/tests/wave/io/test_ndbc.py b/mhkit/tests/wave/io/test_ndbc.py
index 80971213..aa5b86a9 100644
--- a/mhkit/tests/wave/io/test_ndbc.py
+++ b/mhkit/tests/wave/io/test_ndbc.py
@@ -84,7 +84,7 @@ def setUpClass(self):
         }
         self.filenames = ["46042w1996.txt.gz", "46029w1997.txt.gz", "46029w1998.txt.gz"]
         self.swden = pd.read_csv(
-            join(datadir, self.filenames[0]), sep=r"\\s+", compression="gzip"
+            join(datadir, self.filenames[0]), sep=r"\s+", compression="gzip"
         )
 
         buoy = "42012"