diff --git a/mio/bin/t03.c b/mio/bin/t03.c
index 5b5ca5d..c16a27e 100644
--- a/mio/bin/t03.c
+++ b/mio/bin/t03.c
@@ -120,6 +120,7 @@ int main (int argc, char* argv[])
 	for (i = 1; i < argc; i++)
 	{
 		if (strcmp(argv[i], "--permit-word-key") == 0) o |= MIO_JSON_PERMIT_WORD_KEY;
+		if (strcmp(argv[i], "--optional-comma") == 0) o |= MIO_JSON_OPTIONAL_COMMA;
 	}
 
 	mio = mio_open(MIO_NULL, 0, MIO_NULL, 512, MIO_NULL);
diff --git a/mio/lib/json.c b/mio/lib/json.c
index b3b5dd4..db19440 100644
--- a/mio/lib/json.c
+++ b/mio/lib/json.c
@@ -503,8 +503,15 @@ static int handle_char_in_array (mio_json_t* json, mio_ooci_t c)
 	{
 		if (json->state_stack->u.ia.got_value)
 		{
-			mio_seterrbfmt (json->mio, MIO_EINVAL, "comma required in array - %jc", (mio_ooch_t)c);
-			return -1;
+			if (json->option & MIO_JSON_OPTIONAL_COMMA)
+			{
+				json->state_stack->u.ia.got_value = 0;
+			}
+			else
+			{
+				mio_seterrbfmt (json->mio, MIO_EINVAL, "comma required in array - %jc", (mio_ooch_t)c);
+				return -1;
+			}
 		}
 
 		if (c == '\"')
@@ -589,8 +596,14 @@ static int handle_char_in_object (mio_json_t* json, mio_ooci_t c)
 		}
 		else if (json->state_stack->u.io.state == 3)
 		{
-			mio_seterrbfmt (json->mio, MIO_EINVAL, "comma required in object - %jc", (mio_ooch_t)c);
-			return -1;
+			if (json->option & MIO_JSON_OPTIONAL_COMMA)
+			{
+				json->state_stack->u.io.state = 0;
+			}
+			else
+			{
+				mio_seterrbfmt (json->mio, MIO_EINVAL, "comma required in object - %jc", (mio_ooch_t)c);
+			}
 		}
 
 		if (c == '\"')