diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 5ba4a4bed7..fd97d9c286 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -2514,6 +2514,10 @@ JSON_HEDLEY_DIAGNOSTIC_POP
     #define JSON_EXPLICIT explicit
 #endif
 
+#ifndef JSON_DIAGNOSTICS
+    #define JSON_DIAGNOSTICS 0
+#endif
+
 
 namespace nlohmann
 {