diff --git a/dcm2bids/participant.py b/dcm2bids/participant.py
index 61f27f0b..2956f721 100644
--- a/dcm2bids/participant.py
+++ b/dcm2bids/participant.py
@@ -35,10 +35,13 @@ def name(self, name):
         """ Prepend 'sub-' if necessary"""
         if name.startswith("sub-"):
             self._name = name
-
         else:
             self._name = "sub-" + name
 
+        if not self._name.replace('sub-', '').isalnum():
+            raise NameError(f"Participant '{self._name.replace('sub-', '')}' "
+                            "should contains only alphanumeric characters.")
+
     @property
     def session(self):
         """