diff --git a/dcicutils/structured_data.py b/dcicutils/structured_data.py
index 1d2fa95ec..ae3424203 100644
--- a/dcicutils/structured_data.py
+++ b/dcicutils/structured_data.py
@@ -717,7 +717,7 @@ def _ref_exists_single(self, type_name: str, value: str) -> Tuple[bool, Optional
             for item in items:
                 if (ivalue := next((item[iproperty] for iproperty in iproperties if iproperty in item), None)):
                     if isinstance(ivalue, list) and value in ivalue or ivalue == value:
-                        return True, ivalue if is_uuid(ivalue) else None
+                        return True, (ivalue if isinstance(ivalue, str) and is_uuid(ivalue) else None)
         if (value := self.get_metadata(f"/{type_name}/{value}")) is None:
             return False, None
         return True, value.get("uuid")
diff --git a/pyproject.toml b/pyproject.toml
index 1cf79ab70..e2a6273a6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "dcicutils"
-version = "8.7.2.1b1"  # TODO: To become 8.8.0
+version = "8.7.2.1b2"  # TODO: To become 8.8.0
 description = "Utility package for interacting with the 4DN Data Portal and other 4DN resources"
 authors = ["4DN-DCIC Team <support@4dnucleome.org>"]
 license = "MIT"