diff --git a/projects/njs/njs_process_script_fuzzer.c b/projects/njs/njs_process_script_fuzzer.c
index b90425d9f..1a1ac0f7d 100644
--- a/projects/njs/njs_process_script_fuzzer.c
+++ b/projects/njs/njs_process_script_fuzzer.c
@@ -674,8 +674,9 @@ lvlhsh_pool_free(void *pool, void *p, size_t size)
 int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   if (size == 0) return 0;
 
-  char* input = malloc(size);
+  char* input = malloc(size + 1);
   memcpy(input, data, size);
+  input[size] = 0;
   nxt_str_t line = {size, input};
 
   njs_vm_t      *vm;