diff --git a/include/rapidjson/internal/biginteger.h b/include/rapidjson/internal/biginteger.h
index 514a176..af48738 100644
--- a/include/rapidjson/internal/biginteger.h
+++ b/include/rapidjson/internal/biginteger.h
@@ -19,7 +19,11 @@
 
 #if defined(_MSC_VER) && !defined(__INTEL_COMPILER) && defined(_M_AMD64)
 #include <intrin.h> // for _umul128
+#if !defined(_ARM64EC_)
 #pragma intrinsic(_umul128)
+#else
+#pragma comment(lib,"softintrin")
+#endif
 #endif
 
 RAPIDJSON_NAMESPACE_BEGIN
diff --git a/include/rapidjson/internal/diyfp.h b/include/rapidjson/internal/diyfp.h
index a40797e..f7d4653 100644
--- a/include/rapidjson/internal/diyfp.h
+++ b/include/rapidjson/internal/diyfp.h
@@ -25,7 +25,11 @@
 
 #if defined(_MSC_VER) && defined(_M_AMD64) && !defined(__INTEL_COMPILER)
 #include <intrin.h>
+#if !defined(_ARM64EC_)
 #pragma intrinsic(_umul128)
+#else
+#pragma comment(lib,"softintrin")
+#endif
 #endif
 
 RAPIDJSON_NAMESPACE_BEGIN