diff --git a/extmod/modplatform.h b/extmod/modplatform.h
index 95bf073fbd90ffac5453fab7969c8465f3f0c5e5..56a50e53c5445541bb008ec9463adcf36ba4feb9 100644
--- a/extmod/modplatform.h
+++ b/extmod/modplatform.h
@@ -43,6 +43,8 @@
 #define MICROPY_PLATFORM_ARCH   "x86"
 #elif defined(__xtensa__)
 #define MICROPY_PLATFORM_ARCH   "xtensa"
+#elif defined(__riscv)
+#define MICROPY_PLATFORM_ARCH   "riscv"
 #else
 #define MICROPY_PLATFORM_ARCH   ""
 #endif