diff --git a/gto/constants.py b/gto/constants.py
index 8ac794bd..0fd294d6 100644
--- a/gto/constants.py
+++ b/gto/constants.py
@@ -41,7 +41,7 @@ def tag_to_name(value):
     return value.replace(SEPARATOR_IN_TAG, SEPARATOR_IN_NAME)
 
 
-dirname = "[a-z0-9-_./]+"  # improve?
+dirname = "[a-zA-Z0-9-_./]+"  # improve?
 name = r"[a-z0-9]([a-z0-9-/_]*[a-z0-9])?"
 semver = r"(?P<major>0|[1-9]\d*)\.(?P<minor>0|[1-9]\d*)\.(?P<patch>0|[1-9]\d*)(?:-(?P<prerelease>(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+(?P<buildmetadata>[0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?"
 counter = "?P<counter>[0-9]+"