1 files changed, 3 insertions, 1 deletions
diff --git a/ext/json/parser/parser.rl b/ext/json/parser/parser.rl
index a252b552c6..6ebb2f6fac 100644
--- a/ext/json/parser/parser.rl
+++ b/ext/json/parser/parser.rl
@@ -73,10 +73,12 @@ RBIMPL_ATTR_NORETURN()
 #endif
 static void raise_parse_error(const char *format, const char *start)
 {
+    char buffer[PARSE_ERROR_FRAGMENT_LEN + 1];
+
     size_t len = strnlen(start, PARSE_ERROR_FRAGMENT_LEN);
     const char *ptr = start;
+
     if (len == PARSE_ERROR_FRAGMENT_LEN) {
-        char buffer[PARSE_ERROR_FRAGMENT_LEN + 1];
         MEMCPY(buffer, start, char, PARSE_ERROR_FRAGMENT_LEN);
         buffer[PARSE_ERROR_FRAGMENT_LEN] = '\0';
         ptr = buffer;