diff --git a/pkg/oss/policy.go b/pkg/oss/policy.go
index a286eed..c1d8a2a 100644
--- a/pkg/oss/policy.go
+++ b/pkg/oss/policy.go
@@ -95,6 +95,8 @@ func GetPolicyURL(ctx context.Context, path string) (string, error) {
 		contentType = "image/tiff"
 	case ".svg":
 		contentType = "image/svg+xml"
+	case ".pdf":
+		contentType = "application/pdf"
 	default:
 		return "", fmt.Errorf("unsupported file type: %s", ext)
 	}