diff --git a/src/include/lwip/apps/httpd_opts.h b/src/include/lwip/apps/httpd_opts.h
index fd6b4145..871ced45 100644
--- a/src/include/lwip/apps/httpd_opts.h
+++ b/src/include/lwip/apps/httpd_opts.h
@@ -87,7 +87,7 @@
 
 /** This string is passed in the HTTP header as "Server: " */
 #ifndef HTTPD_SERVER_AGENT
-#define HTTPD_SERVER_AGENT "lwIP/"LWIP_VERSION_STRING" (http://savannah.nongnu.org/projects/lwip)"
+#define HTTPD_SERVER_AGENT "lwIP/" LWIP_VERSION_STRING " (http://savannah.nongnu.org/projects/lwip)"
 #endif
 
 /** Set this to 1 if you want to include code that creates HTTP headers