diff --git a/blake3_dispatch.c b/blake3_dispatch.c
index 6518478..3b97e89 100644
--- a/blake3_dispatch.c
+++ b/blake3_dispatch.c
@@ -4,6 +4,23 @@
 
 #include "blake3_impl.h"
 
+/* Force disable x86-64 assembly paths if not building for x86-64 */
+#if !defined(__x86_64__) && !defined(_M_X64)
+  #ifndef BLAKE3_NO_SSE2
+    #define BLAKE3_NO_SSE2 1
+  #endif
+  #ifndef BLAKE3_NO_SSE41
+    #define BLAKE3_NO_SSE41 1
+  #endif
+  #ifndef BLAKE3_NO_AVX2
+    #define BLAKE3_NO_AVX2 1
+  #endif
+  #ifndef BLAKE3_NO_AVX512
+    #define BLAKE3_NO_AVX512 1
+  #endif
+  #undef IS_X86
+#endif
+
 #if defined(IS_X86)
 #if defined(_MSC_VER)
 #include <intrin.h>
diff --git a/config.m4 b/config.m4
index 3b0e790..ef0a4f7 100644
--- a/config.m4
+++ b/config.m4
@@ -3,5 +3,19 @@ PHP_ARG_ENABLE(blake3,
 [--enable-blake3           Enable BLAKE3 Extension])
 
 if test "$PHP_BLAKE3" != "no"; then
-    PHP_NEW_EXTENSION(blake3, php_blake3.c blake3.c blake3_dispatch.c blake3_portable.c blake3_sse2_x86-64_unix.S blake3_sse41_x86-64_unix.S blake3_avx2_x86-64_unix.S blake3_avx512_x86-64_unix.S, $ext_shared)
-fi
\ No newline at end of file
+    dnl Detect target CPU architecture
+    AC_MSG_CHECKING([for blake3 architecture optimization])
+    case "$host_cpu" in
+      x86_64|amd64)
+        AC_MSG_RESULT([x86_64 (enabling SSE/AVX assembly)])
+        BLAKE3_ASM_SOURCES="blake3_sse2_x86-64_unix.S blake3_sse41_x86-64_unix.S blake3_avx2_x86-64_unix.S blake3_avx512_x86-64_unix.S"
+        ;;
+      *)
+        AC_MSG_RESULT([$host_cpu (using portable C implementation)])
+        BLAKE3_ASM_SOURCES=""
+        ;;
+    esac
+
+    dnl Pass detected assembly sources to extension build
+    PHP_NEW_EXTENSION(blake3, php_blake3.c blake3.c blake3_dispatch.c blake3_portable.c $BLAKE3_ASM_SOURCES, $ext_shared)
+fi