diff --git a/ltfatpy/tests/gabor/test_instfreqplot.py b/ltfatpy/tests/gabor/test_instfreqplot.py
index 0cf7e3ac63611903959db8f90a531de15685e035..1a7811737de3ea2df36d5ce8a963a3c4b4a2ebd8 100644
--- a/ltfatpy/tests/gabor/test_instfreqplot.py
+++ b/ltfatpy/tests/gabor/test_instfreqplot.py
@@ -107,8 +107,9 @@ class TestInstfreqplot(unittest.TestCase):
         for inputs, outputs in data:
             out = instfreqplot(**inputs)
             msg = ('Wrong value in output of instfreqplot with inputs ' +
-                   str(inputs))
-            assert_allclose(out, outputs[0], rtol=2e-15, err_msg=msg)
+                   str(inputs) +
+                   '\nMaximal error: ' + str(np.max(np.abs(outputs[0] - out))))
+            assert_allclose(out, outputs[0], atol=1e-13, err_msg=msg)
 
 
 if __name__ == '__main__':