diff --git a/ext/random/randomizer.c b/ext/random/randomizer.c
index 76ff5bf590a88..d732628a98d2d 100644
--- a/ext/random/randomizer.c
+++ b/ext/random/randomizer.c
@@ -26,6 +26,7 @@
 
 #include "Zend/zend_enum.h"
 #include "Zend/zend_exceptions.h"
+#include "zend_portability.h"
 
 static inline void randomizer_common_init(php_random_randomizer *randomizer, zend_object *engine_object) {
 	if (engine_object->ce->type == ZEND_INTERNAL_CLASS) {
@@ -278,7 +279,6 @@ PHP_METHOD(Random_Randomizer, getBytes)
 
 	zend_string *retval;
 	zend_long user_length;
-	size_t total_size = 0;
 
 	ZEND_PARSE_PARAMETERS_START(1, 1)
 		Z_PARAM_LONG(user_length)
@@ -291,22 +291,36 @@ PHP_METHOD(Random_Randomizer, getBytes)
 
 	size_t length = (size_t)user_length;
 	retval = zend_string_alloc(length, 0);
+	char *rptr = ZSTR_VAL(retval);
 
-	while (total_size < length) {
+	size_t to_read = length;
+	while (to_read > 0) {
 		php_random_result result = engine.algo->generate(engine.state);
 		if (EG(exception)) {
 			zend_string_free(retval);
 			RETURN_THROWS();
 		}
-		for (size_t i = 0; i < result.size; i++) {
-			ZSTR_VAL(retval)[total_size++] = (result.result >> (i * 8)) & 0xff;
-			if (total_size >= length) {
-				break;
+		uint64_t tmp_ret = result.result;
+		if (to_read >= sizeof(uint64_t) && result.size == sizeof(uint64_t)) {
+#ifdef WORDS_BIGENDIAN
+			tmp_ret = ZEND_BYTES_SWAP64(tmp_ret);
+#endif
+			memcpy(rptr, &tmp_ret, sizeof(uint64_t));
+			to_read -= sizeof(uint64_t);
+			rptr += sizeof(uint64_t);
+		} else {
+			for (size_t i = 0; i < result.size; i++) {
+				*rptr++ = tmp_ret & 0xff;
+				tmp_ret >>= 8;
+				to_read--;
+				if (to_read == 0) {
+					break;
+				}
 			}
 		}
 	}
 
-	ZSTR_VAL(retval)[length] = '\0';
+	*rptr = '\0';
 	RETURN_STR(retval);
 }
 /* }}} */