diff --git a/eralchemy/models.py b/eralchemy/models.py
index 96c43da0a9b9ae5abdfc1096570278fce731ff11..08f413c667915ef8039dc6cad5a32afd3296b9c1 100644
--- a/eralchemy/models.py
+++ b/eralchemy/models.py
@@ -39,7 +39,7 @@ class Drawable(ABC):
 
 
 def sanitize_mermaid(text: str, *, is_er: bool = False):
-    RE = re.compile("[^0-9a-zA-Z_-]+")
+    RE = re.compile("[^0-9a-zA-Z._-]+")
     """Mermaid does not allow special characters in column names"""
     if not text:
         return text