diff --git a/src/parser.h b/src/parser.h
index 16e72a4..edffbb4 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -136,7 +136,8 @@ private:
       }
     }
     for (;;) {
-      result = (char *)memchr(result, '"', bufEnd - result);
+      result = result == nullptr ? nullptr
+                                 : (char *)memchr(result, '"', bufEnd - result);
       if (result == nullptr) {
         if (complete) {
           return S_REJECT;