diff --git a/data_diff/databases/base.py b/data_diff/databases/base.py
index 8caa6817..0aa8ff50 100644
--- a/data_diff/databases/base.py
+++ b/data_diff/databases/base.py
@@ -1069,7 +1069,7 @@ def _refine_coltypes(
                     )
                 else:
                     assert col_name in col_dict
-                    col_dict[col_name] = String_UUID()
+                    col_dict[col_name] = String_VaryingAlphanum()
                     continue
 
             if self.SUPPORTS_ALPHANUMS:  # Anything but MySQL (so far)
diff --git a/data_diff/utils.py b/data_diff/utils.py
index ee4a0f17..d8caa9cb 100644
--- a/data_diff/utils.py
+++ b/data_diff/utils.py
@@ -113,7 +113,7 @@ def as_insensitive(self):
 
 # -- Alphanumerics --
 
-alphanums = " -" + string.digits + string.ascii_uppercase + "_" + string.ascii_lowercase
+alphanums = string.digits + string.ascii_lowercase + string.ascii_uppercase
 
 
 @attrs.define(frozen=True)