diff --git a/runtime/fastly/handler.cpp b/runtime/fastly/handler.cpp
index 7e16cc4511..a58328a751 100644
--- a/runtime/fastly/handler.cpp
+++ b/runtime/fastly/handler.cpp
@@ -48,8 +48,9 @@ bool handle_incoming(host_api::Request req) {
   __wasilibc_ensure_environ();
 
   if (ENGINE->debug_logging_enabled()) {
+    const char *ver = getenv("FASTLY_SERVICE_VERSION");
     printf("Running JS handleRequest function for Fastly Compute service version %s\n",
-           getenv("FASTLY_SERVICE_VERSION"));
+           ver ? ver : "unknown");
     fflush(stdout);
   }