diff --git a/drivers/usbdev/cdcacm.c b/drivers/usbdev/cdcacm.c
index b4b5173678b..6767fd8e521 100644
--- a/drivers/usbdev/cdcacm.c
+++ b/drivers/usbdev/cdcacm.c
@@ -111,7 +111,7 @@ struct cdcacm_dev_s
    */
 
   struct cdcacm_req_s wrreqs[CONFIG_CDCACM_NWRREQS];
-  struct cdcacm_req_s rdreqs[CONFIG_CDCACM_NWRREQS];
+  struct cdcacm_req_s rdreqs[CONFIG_CDCACM_NRDREQS];
 
   /* Serial I/O buffers */