diff --git a/chip/stm32/config-stm32f373.h b/chip/stm32/config-stm32f373.h
index 2b742bafdf..2553702877 100644
--- a/chip/stm32/config-stm32f373.h
+++ b/chip/stm32/config-stm32f373.h
@@ -38,4 +38,4 @@
 #define CONFIG_IRQ_COUNT 81
 
 /* STM32F3 has a larger USB RAM */
-#define CONFIG_USB_RAM_SIZE 1024
+#define CONFIG_USB_RAM_SIZE 512
diff --git a/include/usb.h b/include/usb.h
index bce830ebb3..65dc8236f4 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -226,7 +226,7 @@ struct usb_endpoint_descriptor {
 /* Helpers for managing the USB controller dedicated RAM */
 
 /* primitive to access the words in USB RAM */
-#ifdef CHIP_FAMILY_STM32F0
+#if defined(CHIP_FAMILY_STM32F0) || defined(CHIP_FAMILY_STM32F3)
 typedef uint16_t usb_uint;
 #else
 /* older chips use a weird addressing were 16-bit words are 32-bit appart */