diff --git a/Zend/zend_cpuinfo.h b/Zend/zend_cpuinfo.h
index 513dacfd08f5..855e245beafe 100644
--- a/Zend/zend_cpuinfo.h
+++ b/Zend/zend_cpuinfo.h
@@ -272,7 +272,10 @@ static zend_always_inline int zend_cpu_supports_avx512_vbmi(void) {
 #endif
 
 /* __builtin_cpu_supports has pclmul from gcc9 and clang 19 */
-#if defined(PHP_HAVE_BUILTIN_CPU_SUPPORTS) && (!defined(__GNUC__) || (defined(__clang__) && __clang_major__ >= 19) || (ZEND_GCC_VERSION >= 9000))
+#if defined(PHP_HAVE_BUILTIN_CPU_SUPPORTS) && (defined(__x86_64__) || defined(__i386__)) && \
+	( \
+		(!defined(__GNUC__) || (defined(__clang__) && __clang_major__ >= 19) || (ZEND_GCC_VERSION >= 9000)) \
+	)
 ZEND_NO_SANITIZE_ADDRESS
 static inline int zend_cpu_supports_pclmul(void) {
 #ifdef PHP_HAVE_BUILTIN_CPU_INIT
@@ -287,7 +290,11 @@ static inline int zend_cpu_supports_pclmul(void) {
 #endif
 
 /* __builtin_cpu_supports has cldemote from gcc11 and clang 19 */
-#if defined(PHP_HAVE_BUILTIN_CPU_SUPPORTS) && ((defined(__clang__) && (__clang_major__ >= 19)) || (!defined(__clang__) && defined(__GNUC__) && (ZEND_GCC_VERSION >= 11000)))
+#if defined(PHP_HAVE_BUILTIN_CPU_SUPPORTS) && (defined(__x86_64__) || defined(__i386__)) && \
+	( \
+		(defined(__clang__) && (__clang_major__ >= 19)) || \
+		(!defined(__clang__) && defined(__GNUC__) && (ZEND_GCC_VERSION >= 11000)) \
+	)
 #define HAVE_ZEND_CPU_SUPPORTS_CLDEMOTE 1
 ZEND_NO_SANITIZE_ADDRESS
 static inline int zend_cpu_supports_cldemote(void) {
diff --git a/ext/lexbor/config.m4 b/ext/lexbor/config.m4
index 21fabcd0ddb0..a75f490e77cc 100644
--- a/ext/lexbor/config.m4
+++ b/ext/lexbor/config.m4
@@ -1,4 +1,4 @@
-PHP_LEXBOR_CFLAGS="-I@ext_srcdir@/"
+PHP_LEXBOR_CFLAGS="-Wno-unknown-warning-option -Wno-unterminated-string-initialization -I@ext_srcdir@/"
 LEXBOR_DIR="lexbor"
 
 AC_DEFINE([HAVE_LEXBOR], [1], [Define to 1 if the PHP extension 'lexbor' is available.])