diff --git a/Source/C++/Core/Ap4Config.h b/Source/C++/Core/Ap4Config.h
index 5b9e83e..e4fff8e 100644
--- a/Source/C++/Core/Ap4Config.h
+++ b/Source/C++/Core/Ap4Config.h
@@ -56,7 +56,7 @@
 #if defined(_M_IX86) || defined(_M_X64) || defined(_M_ARM) || defined(_M_ARM64)
 #define AP4_PLATFORM_BYTE_ORDER AP4_PLATFORM_BYTE_ORDER_LITTLE_ENDIAN
 #endif
-#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__arm64__) || defined(__aarch64__) || (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__arm64__) || defined(__aarch64__) || defined(__riscv) || (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
 #define AP4_PLATFORM_BYTE_ORDER AP4_PLATFORM_BYTE_ORDER_LITTLE_ENDIAN
 #endif
 #endif
