diff --git a/src/common/tusb_fifo.h b/src/common/tusb_fifo.h
index 86ba59059..a3829e38e 100644
--- a/src/common/tusb_fifo.h
+++ b/src/common/tusb_fifo.h
@@ -289,6 +289,12 @@ TU_ATTR_ALWAYS_INLINE static inline bool tu_fifo_empty(const tu_fifo_t *f) {
   return wr_idx == rd_idx;
 }
 
+// Suppress IAR warning
+// Warning[Pa082]: undefined behavior: the order of volatile accesses is undefined in this statement
+#if defined(__ICCARM__)
+#pragma diag_suppress = Pa082
+#endif
+
 // return number of items in fifo, capped to fifo's depth
 TU_ATTR_ALWAYS_INLINE static inline uint16_t tu_fifo_count(const tu_fifo_t *f) {
   return tu_min16(tu_ff_overflow_count(f->depth, f->wr_idx, f->rd_idx), f->depth);
@@ -303,6 +309,10 @@ TU_ATTR_ALWAYS_INLINE static inline uint16_t tu_fifo_remaining(const tu_fifo_t *
   return tu_ff_remaining_local(f->depth, f->wr_idx, f->rd_idx);
 }
 
+#if defined(__ICCARM__)
+ #pragma diag_default=Pa082
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/tusb.c b/src/tusb.c
index 9af5e3c98..8dce90391 100644
--- a/src/tusb.c
+++ b/src/tusb.c
@@ -39,6 +39,12 @@
 #include "host/usbh_pvt.h"
 #endif
 
+// Suppress IAR warning
+// Warning[Pe111]: statement is unreachable
+#if defined(__ICCARM__)
+#pragma diag_suppress = Pe111
+#endif
+
 tusb_role_t _tusb_rhport_role[TUP_USBIP_CONTROLLER_NUM] = { TUSB_ROLE_INVALID };
 
 //--------------------------------------------------------------------