diff --git a/pandas_schema/validation.py b/pandas_schema/validation.py
index 9d5b2b4..837ea34 100644
--- a/pandas_schema/validation.py
+++ b/pandas_schema/validation.py
@@ -204,7 +204,7 @@ def default_message(self):
         return 'was not in the range [{}, {})'.format(self.min, self.max)
 
     def validate(self, series: pd.Series) -> pd.Series:
-        series = pd.to_numeric(series)
+        series = pd.to_numeric(series, errors='coerce')
         return (series >= self.min) & (series < self.max)