diff --git a/extension/php_xhprof.h b/extension/php_xhprof.h
index fc518229..3360e779 100755
--- a/extension/php_xhprof.h
+++ b/extension/php_xhprof.h
@@ -193,8 +193,8 @@ ZEND_DLEXPORT zend_op_array* hp_compile_file(zend_file_handle *file_handle, int
 static zend_op_array * (*_zend_compile_string) (zval *source_string, char *filename);
 ZEND_DLEXPORT zend_op_array* hp_compile_string(zval *source_string, char *filename);
 #else
-static zend_op_array * (*_zend_compile_string) (zval *source_string, const char *filename);
-ZEND_DLEXPORT zend_op_array* hp_compile_string(zval *source_string, const char *filename);
+static zend_op_array * (*_zend_compile_string) (zend_string *source_string, const char *filename);
+ZEND_DLEXPORT zend_op_array* hp_compile_string(zend_string *source_string, const char *filename);
 #endif
 
 /**
diff --git a/extension/xhprof.c b/extension/xhprof.c
index f7861517..d3eea0f6 100755
--- a/extension/xhprof.c
+++ b/extension/xhprof.c
@@ -1229,7 +1229,7 @@ ZEND_DLEXPORT zend_op_array* hp_compile_file(zend_file_handle *file_handle, int
 #if PHP_VERSION_ID < 80000
 ZEND_DLEXPORT zend_op_array* hp_compile_string(zval *source_string, char *filename)
 #else
-ZEND_DLEXPORT zend_op_array* hp_compile_string(zval *source_string, const char *filename)
+ZEND_DLEXPORT zend_op_array* hp_compile_string(zend_string *source_string, const char *filename)
 #endif
 {
     if (!XHPROF_G(enabled)) {