diff --git a/src/Concerns/TracesHttpRequests.php b/src/Concerns/TracesHttpRequests.php
index fe38437..237c9ee 100644
--- a/src/Concerns/TracesHttpRequests.php
+++ b/src/Concerns/TracesHttpRequests.php
@@ -148,7 +148,7 @@ private function calculateSpanName(Request $request): string
         // includes the name of the route, if it has one.
         $routeName = $route->getName();
 
-        if (Str::startsWith($routeName, 'generated::')) {
+        if (($routeName !== null) && Str::startsWith($routeName, 'generated::')) {
             // This is a route name generated by for a closure when caching
             // routes. We don't want to include these in the trace, so we'll
             // just set the name to null and default to the route path.