diff --git a/tinyusb/host/ohci/ohci.c b/tinyusb/host/ohci/ohci.c
index ab27c6e5a..197f3fb02 100644
--- a/tinyusb/host/ohci/ohci.c
+++ b/tinyusb/host/ohci/ohci.c
@@ -135,7 +135,7 @@ enum {
 //--------------------------------------------------------------------+
 // INTERNAL OBJECT & FUNCTION DECLARATION
 //--------------------------------------------------------------------+
-TUSB_CFG_ATTR_USBRAM STATIC_VAR ohci_data_t ohci_data;
+TUSB_CFG_ATTR_USBRAM ATTR_ALIGNED(256) STATIC_VAR ohci_data_t ohci_data;
 
 static ohci_ed_t * const p_ed_head[] =
 {
diff --git a/tinyusb/host/ohci/ohci.h b/tinyusb/host/ohci/ohci.h
index 43875dcb3..f03ef94b9 100644
--- a/tinyusb/host/ohci/ohci.h
+++ b/tinyusb/host/ohci/ohci.h
@@ -77,9 +77,11 @@ typedef struct {
   volatile uint16_t frame_number;
   volatile uint16_t frame_pad;
   volatile uint32_t done_head;
-  uint8_t reserved[116]; // TODO try to make use of this area if possible
+  uint8_t reserved[116+4];  // TODO try to make use of this area if possible, extra 4 byte to make the whole struct size = 256
 }ohci_hcca_t; // ATTR_ALIGNED(256)
 
+STATIC_ASSERT( sizeof(ohci_hcca_t) == 256, "size is not correct" );
+
 typedef struct {
   uint32_t reserved[2];
   volatile uint32_t next_td;