diff --git a/neurokit2/ecg/ecg_quality.py b/neurokit2/ecg/ecg_quality.py
index 1f6cadb27f..2275c51493 100644
--- a/neurokit2/ecg/ecg_quality.py
+++ b/neurokit2/ecg/ecg_quality.py
@@ -57,7 +57,7 @@ def ecg_quality(
     -------
     array or str
         Vector containing the quality index ranging from 0 to 1 for ``"averageQRS"`` method,
-        returns string classification (``Unacceptable``, ``Barely Acceptable`` or ``Excellent``)
+        returns string classification (``Unacceptable``, ``Barely acceptable`` or ``Excellent``)
         of the signal for ``"zhao2018"`` method.
 
     See Also