diff --git a/internal/github/github.go b/internal/github/github.go
index 6c2f380ff..4bbfc07e7 100644
--- a/internal/github/github.go
+++ b/internal/github/github.go
@@ -196,11 +196,16 @@ func (c *GithubConfig) PREvidenceForCommitV2(commit string) ([]*types.PREvidence
 				return pullRequestsEvidence, err
 			}
 
+			committerUsername := ""
+			if c.Commit.Committer.User != nil {
+				committerUsername = string(c.Commit.Committer.User.Login)
+			}
+
 			evidence.Commits = append(evidence.Commits, types.Commit{
 				SHA:               string(c.Commit.Oid),
 				Message:           string(c.Commit.MessageHeadline),
 				Committer:         fmt.Sprintf("%s <%s>", string(c.Commit.Committer.Name), string(c.Commit.Committer.Email)),
-				CommitterUsername: string(c.Commit.Committer.User.Login),
+				CommitterUsername: committerUsername,
 				Timestamp:         timestamp.Unix(),
 				Branch:            string(pr.HeadRefName),
 				URL:               string(c.Commit.URL),
diff --git a/internal/types/types.go b/internal/types/types.go
index 303182729..cc406182b 100644
--- a/internal/types/types.go
+++ b/internal/types/types.go
@@ -23,7 +23,7 @@ type Commit struct {
 	SHA               string `json:"sha1"`
 	Message           string `json:"message"`
 	Committer         string `json:"author"`
-	CommitterUsername string `json:"author_username"`
+	CommitterUsername string `json:"author_username,omitempty"`
 	Timestamp         int64  `json:"timestamp"`
 	Branch            string `json:"branch"`
 	URL               string `json:"url,omitempty"`