diff --git a/src/pyosmeta/models/base.py b/src/pyosmeta/models/base.py
index 374b0e6..64356a4 100644
--- a/src/pyosmeta/models/base.py
+++ b/src/pyosmeta/models/base.py
@@ -256,7 +256,7 @@ class ReviewModel(BaseModel):
     categories: Optional[list[str]] = None
     editor: ReviewUser | list[ReviewUser] | None = None
     eic: ReviewUser | list[ReviewUser] | None = None
-    reviewers: list[ReviewUser] = Field(default_factory=list)
+    reviewers: list[ReviewUser] | None = None
     archive: str | None = None
     version_accepted: str | None = None
     date_accepted: str | None = Field(
diff --git a/src/pyosmeta/parse_issues.py b/src/pyosmeta/parse_issues.py
index 77f4a9b..b0464b1 100644
--- a/src/pyosmeta/parse_issues.py
+++ b/src/pyosmeta/parse_issues.py
@@ -340,7 +340,7 @@ def parse_issues(
 
     def get_contributor_data(
         self, line: str
-    ) -> Union[ReviewUser, List[ReviewUser]]:
+    ) -> Union[ReviewUser, List[ReviewUser], None]:
         """Parse names for various review roles from issue metadata.
 
         Parameters
@@ -358,6 +358,8 @@ def get_contributor_data(
         users = line.split(",")
         models = [parse_user_names(username=user) for user in users]
         models = [model for model in models if model is not None]
+        if len(models) == 0:
+            return None
         if len(models) == 1:
             models = models[0]
         return models
diff --git a/src/pyosmeta/utils_parse.py b/src/pyosmeta/utils_parse.py
index b3b0eb5..43d8ee5 100644
--- a/src/pyosmeta/utils_parse.py
+++ b/src/pyosmeta/utils_parse.py
@@ -45,5 +45,6 @@ def parse_user_names(username: str) -> ReviewUser | None:
             "github_username": clean_name(names[0]),
             "name": "",
         }
-
+    if (parsed["github_username"] == "") and (parsed["name"] == ""):
+        return None
     return ReviewUser(**parsed)