diff --git a/CMakeLists.txt b/CMakeLists.txt
index 05c25d4..47c770c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.5)
 project(parson C)
 
+set(C_STANDARD 89)
+
 include (GNUInstallDirs)
 
 set(PARSON_VERSION 1.5.3)