diff --git a/configs/olimex-stm32-p207/src/stm32_usb.c b/configs/olimex-stm32-p207/src/stm32_usb.c
index 0dc678d5f21..c9b2c968aae 100644
--- a/configs/olimex-stm32-p207/src/stm32_usb.c
+++ b/configs/olimex-stm32-p207/src/stm32_usb.c
@@ -169,7 +169,9 @@ void stm32_usbinitialize(void)
 int stm32_usbhost_initialize(void)
 {
   int pid;
+#if defined(CONFIG_USBHOST_HUB) || defined(CONFIG_USBHOST_MSC) || defined(CONFIG_USBHOST_CDCACM)
   int ret;
+#endif
 
   /* First, register all of the class drivers needed to support the drivers
    * that we care about: