diff --git a/pyproject.toml b/pyproject.toml
index 88bad095..27454620 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -30,7 +30,7 @@ dependencies = [
   "numpy",
   "pandas",
   "scipy",
-  "specutils>1.16,<1.18",
+  "specutils>1.16",
   "httpx",
   "rich",
   "tenacity",
diff --git a/src/dysh/spectra/tests/test_spectrum.py b/src/dysh/spectra/tests/test_spectrum.py
index c299a2f4..09f24558 100644
--- a/src/dysh/spectra/tests/test_spectrum.py
+++ b/src/dysh/spectra/tests/test_spectrum.py
@@ -370,7 +370,9 @@ def test_smooth_multi(self):
 
         # Check fitter first.
         g_fit = fit_gauss(self.ss)
-        assert g_fit.stddev.value * 2.35482 == pytest.approx(abs(self.ss.meta["CDELT1"]) * self.ss.meta["FWHM"])
+        assert g_fit.stddev.value * 2.35482 == pytest.approx(
+            abs(self.ss.meta["CDELT1"]) * self.ss.meta["FWHM"], g_fit.stddev.std * 2.35482
+        )
 
         # Now smooth the same Spectrum multiple times.
         sss = self.ss._copy()