2 files changed, 1 insertions, 1 deletions
diff --git a/ext/json/generator/generator.c b/ext/json/generator/generator.c
index 6eea7ff148..21fef2b657 100644
--- a/ext/json/generator/generator.c
+++ b/ext/json/generator/generator.c
@@ -762,7 +762,6 @@ static void generate_json_bignum(FBuffer *buffer, VALUE Vstate, JSON_Generator_S
 {
     VALUE tmp = rb_funcall(obj, i_to_s, 0);
     fbuffer_append_str(buffer, tmp);
-    RB_GC_GUARD(tmp);
 }
 
 static void generate_json_float(FBuffer *buffer, VALUE Vstate, JSON_Generator_State *state, VALUE obj)
diff --git a/ext/json/generator/generator.h b/ext/json/generator/generator.h
index 3220178a8f..4958cf094d 100644
--- a/ext/json/generator/generator.h
+++ b/ext/json/generator/generator.h
@@ -105,6 +105,7 @@ typedef struct JSON_Generator_StateStruct {
     Data_Get_Struct(Vstate, JSON_Generator_State, state);                                       \
     buffer = cState_prepare_buffer(Vstate);                                                     \
     generate_json_##type(buffer, Vstate, state, self);                                          \
+    RB_GC_GUARD(Vstate); \
     return fbuffer_to_s(buffer)
 
 static VALUE mHash_to_json(int argc, VALUE *argv, VALUE self);