diff --git a/src/json.hpp b/src/json.hpp
index ffa46067..57a8f4c7 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -9227,7 +9227,7 @@ basic_json_parser_63:
         }
 
         /// split the string input to reference tokens
-        std::vector<std::string> split(std::string reference_string)
+        static std::vector<std::string> split(std::string reference_string)
         {
             std::vector<std::string> result;
 
diff --git a/src/json.hpp.re2c b/src/json.hpp.re2c
index ced7ffba..cdd96ee9 100644
--- a/src/json.hpp.re2c
+++ b/src/json.hpp.re2c
@@ -8537,7 +8537,7 @@ class basic_json
         }
 
         /// split the string input to reference tokens
-        std::vector<std::string> split(std::string reference_string)
+        static std::vector<std::string> split(std::string reference_string)
         {
             std::vector<std::string> result;